Biology II (SIMPLE EDITOR) Flashcards
(972 cards)
1
Q
tight junctions: function
A
act as a permeability barrier – preventing transport of protein molecules from lumenal side of cell to basolateral side of cell also act to hold neighboring cells together
2
Q
desmosomes: function
A
hold cells together
3
Q
Gap Junctions: function
A
provides a mean for water–soluble molecules to pass from the cytoplasm of one cell to the cytoplasm of another cell
4
Q
type of cells in epidermal region of skin
A
stratified epilthelial cells
5
Q
Cells that secrete many of the proteins that make up structural connective tissue
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fibroblasts
6
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Structural proteins secreted by fibroblasts
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collagen, elastin, reticulin
7
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collagen: features and function
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–triple stranded, insoluble, fibrous protein–highly cross–linked–quite strong and flexible
8
Q
reticulin: features and function
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–thin fiber–not as highly coiled as collagen–found in spleen and lymph nodes
9
Q
elastin: features and function
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–highly cross–linked protein–associated with organs that require elasticity (lungs, skin, blood vessels, etc.)
10
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Cartilage:–type of tissue–cell type–where found
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–connective tissue–special type of fibroblast = chondrocyte–fond in places where stress is put on bodies
11
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bone:–made up of
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–1/3 organic materials (such as collagen)–2/3 inorganic materials (calcium carbonate, calcium phosphate, etc.)
12
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bone:–what secretes collagen in the bone matrix
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–Specialized fibroblast cells called osteoblasts
13
Q
_______ lend(s) flexibility to bones, while ________ lend(s) rigidity
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–Collagen for flexibility–inorganic cystals for rigidity
14
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Mast Cells
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–Release histamines in response to an allergic reaction, infection, or injury
15
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Effect of histamines
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Cause an increase in blood flow to blood vessels in the affected region
16
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Where are mast cells found
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Respiratory tract, GI tract, etc.
17
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Two types of cells that make up nervous system
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(1) Nerve cells (neurons)(2) Support cells (glial cells)
18
Q
Major anatomical features of a neuron
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(1) Cell Body = integrates info(2) Dendrites = Receive info + Transmit info towards cell body(3) Axon = conducts info away from the cell body
19
Q
End of a neuron = ______
A
synaptic bulb
20
Q
Concentration of Na+ and K+ inside vs outside cell
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IN CELL:small Na+LARGE K+OUTSIDE OF CELL:LARGE Na+small K+
21
Q
Concentration of Cl– and HCO3– inside vs. outside of cells
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Cl– = lower inside cellHCO3– = usually lower inside cell also
22
Q
Typically voltage inside cell (compared to outside).Explain
A
Typically ~ –80mV–negative because of leaky K+ channels – so K+ diffuses outside of cell (down its gradient)
23
Q
What is the ATPase Pump
A
Pumps Na+ out of the cell and K+ into the cell(against both of their gradients)
24
Q
Nernst Equation
A
Vio = 2/3 (RT)/(ZF) x log([K+]o/[K+]i)
25
Steps to generation of an action potential:
(1) Stimulus: causes a transient increase in membrane permeability to Na+(2) Depolarization: caused by Na+ influx(3) Flood of Na+ into cell: will occur if cell is depolarized enough(4) Action Potential: generated by the flood of Na+
26
High level steps pre and post action potential
(1) Stimulus(2) Depolarization –> Action Potential(3) Repolarization: K+ channels open and K+ exits the cell(4) Hyperpolarization: Massive amounts of K+ exit the cell(5) Refractory Period: Na+ channels are temporarily inactive (neuron can't generate another action potential
27
The generation of an action potential is an ________ phenomenon, and will always have _______
All–or–nothingWill always have the same magnitude
28
Two factors leading to faster and further action potentials
(1) Myelenation(2) Larger neuronal cross sectional area
29
Glial cells myelenate ________ (part of neuron)
Axons
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Area on axons where there is no myelin
Nodes of Ranvier
31
Type of glial cell that myelenates the CNS
Oligodendrocytes
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Type of glial cell that myelenates the PNS
Schwann Cells
33
Nerve impulse in myelenated neurons
Referred to as saltatory conduction "Jumps" from node to node along the axons – ions can only enter at the Nodes of Ranvier
34
How does an action potential spread through neuromuscular junction
(1) Action potential reaches synaptic terminal(2) Triggers Ca2+ channels to open – Ca2+ flows into synaptic terminal region(3) Synaptic vesicles fuse with presynaptic membrane – causing release of neurotransmitter (often ACh) into synaptic cleft(4) Neurotransmitter diffuses through the cleft – binding to the postsynaptic membrane receptors(5) Causing receptors to change conformation to a channel – allowing Na+ to flow in(6) Na+ flux in leads to depolarization and action potential
35
Excitatory vs. Inhibitory Post Synaptic Potentials
If lets in Na+ === excitatoryIf lets in Cl– or K+ ==== inhibitory
36
How is ACh (Acetylcholine) broken down
the enzyme acetylcholinesterase, which is bound to the postsynaptic membrane, hydrolyzes ACh into acetate and choline–Acetate and choline are transported back into the presynaptic terminal where they are used in the synthesis of Ach
37
Attach bone to muscle
tendon
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attach bone to bone
ligaments
39
Muscles are made up of multinucleated _______, which are made up of ________, which are made up of ________.
Multinucleated Muscle Cells (aka Muscle Fibers) –––> Myofibrils ––––> Sarcomeres
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The _______ contain the contractile units of the muscle
Myofibrils
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the contractile units of the muscle = _____
sarcomeres
42
Sarcomeres are bound by the ________.
Z–line
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Where there is only actin
I–band
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the ______ contains all of the myosin
A–Band
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the ______ is the region in the center of the A–Band, and it only contains myosin.
H Zone
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Thin contractile protein of sarcomeres = _____Thick contractile protein = _______
thin = actinthick = myosin
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_____ are arranged towards the center of the sarcomere (and not attached to the Z–Line)
Myosin
48
Where are myosin heads located
In the terminal regions of myosin
49
Actin filament is composed of a protein subunit called _______ (because the shape is _____).
G Actin (G for globular because the shape is roughly spherical)
50
How can actin filaments grow
by the addition of G actin to the ends of already existing filament
51
Each actin is composed of __________
2 rows of G actin monomers wound around each other to form a helix
52
High level summary of muscle contraction steps
(1) ATP is bound to myosin head (so myosin and actin aren't bound) = relaxed state(2) ATP is hydorlyzed to ADP + Pi ––– myosin undergoes conformational change(3) High energy Myosin–ADP–Pi complex binds to actin(4) Causes release of ADP + Pi from myosin heads –– causing another conformation change of myosin ––––> Actin moves relative to myosin Called the POWER STROKE(5) ATP binds myosin – causing myosin to release actin
53
What causes myosin to be able to bind actin
Tropomyosin is on actin, and covers the myosin binding sitesCa2+ binds to troponin – which is attached to troponin, and causes a conformational change in tropomyosin, uncovering the myosin binding sites on actin
54
Relationship between action potentials and muscle contraction
Action potential travels down T–Tubules, causing release of Ca2+ from sarcoplasmic reticulum into the cytosol (where it can bind to troponin, allowing myosin to bind to actin, allowing for the power stroke)
55
How Ca2+ in cytosol returns to sarcoplasmic reticulum
through Ca2+ –ATPase Pump
56
Eqn for generation of ATP in aerobic conditions (from glucose)
Glucose –––––> CO2 + H20 + 36ATP(slower)
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Eqn for generation of ATP in anaerobic conditions (from glucose)
Glucose ––––––> Lactate + 2ATP(faster)
58
During anaerobic conditions, [lactate] begins to ______, which will case the ph to _______. Effects of this.
[lactate] increases, and pH decreases–some enzymes can no longer function outside of pH range – halting glycolysis and ATP yield
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a grouping of nerve cells = a _______
ganglian
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CNS = ______PNS = ______
CNS = brain + spinal cordPNS = all nerves extending from the spinal cord
61
3 divisions of the vertebrate brain
(1) Forebrain(2) Midbrain(3) Hindbrain
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3 Main subdivisions of the forebrain
(1) Cerebrum(2) Thalamus(3) Hypothalamus
63
The _______ has 2 hemispheres (right and left) which are joined by the ______.
Cerebrum (of the Forebrain); joined by the corpus callosum
64
The Lobes of the cerebrum (and what they are associated with)
(1) Frontal = movement and personality(2) Parietal = touch and stretch sensation(3) Temporal = Hearing(4) Occipital = Vision
65
Outermost layer of the cerebrum = the ______
cerebral cortex
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The cerebral cortex consists of _______ and ______. Locations of both
–gray matter = nerve cell bodies + their dendrites–white matter = myelinated axons of nerve cellsWhite matter is central, gray is on outside"
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Location: White and Gray matter in Cerebrum and Spinal cord
in Cerebrum:White = Central; Gray = Outsidein Spinal Cord:White = Outside; Gray = Central
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3 important landmarks in cerebral cortex
(1) Central Sulcus = groove; separates frontal + parietal lobes(2) Motor Cortex = Controls movement of individual muscles(3) Sensory Cortex = Detects sensations in various parts of the body
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Sensory Homonucleus
Schematic model of human being mapped out on the sensory cortex – showing which neurons register sensations from different body parts
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Thalamus: function
relay station for visual and audio info
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hypothalamus: function
concerned with visceral activities of the body
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pituitary gland: function
master endocrine gland –receives info from hypothalamus and sends out info to regulate the body
73
brainstem: different features
*detects movement and can direct the head and eyes towards it–Midbrain: also senses pleasure + pain–Cerebellum: Resposible for the bulk of regulation + coordination of muscular activity–Pons and Medulla: coordinate visceral activities–Reticular Formation: brainstem core; alerts the brain + inhibits motor and sensory impulses that can induce sleep
74
Muscle that elicits extension (when it contracts) = ______Muscle that elicits bending/flexing = _____"
ExtensorFlexor
75
the nerve pathway involved in a reflex action including at its simplest a sensory nerve and a motor nerve with a synapse between = _______.Can be mono or poly–synaptic"
Reflex Arc–monosynaptic or polysnaptic reflex arcs–can include interneurons (transmit impulses between other neurons)"
76
efferent vs afferent divisions of the PNS
Efferent (AWAY from CNS): Carry nerve impulses:CNS –––––> MuscleAfferent (TO CNS): Carry nerve impulses:Sensory stimuli ––––> CNS
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The Autonomic Nervous system is part of the ______ division of the PNS
Efferent
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One part of the _________ Nervous System is the ___________ Nervous System, which can be divided into the _________ and _________ Systems.
Peripheral –––> Autonomic ––––> Sympathetic + Parasympathetic
79
Where do nerve fibers leave from in the Parasympathetic Nervous System?
Sacral portion of spinal cord; and midbrain and medulla
80
Key functions of Parasympathetic vs Sympathetic Nervous Systems
Parasympathetic = rest and digestSympathetic = fight or flight
81
The preganglionic nerve fibers vs. the postganglionic nerve fibers. When long and short.
In parasympathetic system:pre = longpost = shortIn sympathetic system:pre = shortpost = long
82
What neurotransmitters do different nerve fibers of the parasympathetic and sympathetic systems release?
Parasympathetic System:Pre = AChPos = AChSympathetic System:Pre = AChPost = Norepinephrine
83
Cholingeric Nerve Fibers
Release ACh (Acetylcholine)
84
Most prominent nerve in parasympathetic division
Vagus Nerve ~75% of all neurons in the parasympathetic division are found in the vagus nerve–innervates many organs
85
Sympathetic Division has nerve fibers branching off from
Thoracic and Lumbar regions of the spinal cord
86
How adrenal medulla functions
(1) Preganglionic nerve fibers from thoracic region of spinal cord (sympathetic division) synapse directly with nerve fibers on the adrenal medulla (i.e., there are no postganglionic nerve fibers)(2) Adrenal medulla is stimulated and releases norepinephrine and epinephrine directly into the bloodstream (thus are hormones)–––> thus it is an endocrine gland*causes increase in HR and pupils to dilate
87
somatic nervous system
Part of the PNS related to voluntary movements
88
How somatic nervous system functions
(1) Nerve fibers leave CNS and don't synapse until they reach their effector organ(2) ACh is released(3) Innervating Skeletal Muscle(4) Can be excitatory or inhibitory
89
Some types of sensory receptors (and what they sense)
(1) Mechanoreceptors: Pressure; hearing; balance; blood pressure(2) Nocireceptors: Pain(3) Thermoreceptors: cold and warmth(4) Chemoreceptors: Taste, smell, O2, CO2, glucose levels, etc.(5) Photoreceptors (of retina): Photons
90
How sensory receptors receive, transduce, transmit, info
(1) receptor receives sensory info(2) Stimulus received changes membrane potential of receptor (transduction)(3) If potential changes enough, an action potential results
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Adaptation of Sensory Neurons (and which cells adapt a lot and which don't)
Over time, frequency of action potentials diminishes, so can no longer feel the sensation–Pressure Receptors adapt a lot, and pain do not
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Receptive Field
Axonal branches of a single neuron and the many receptors that the branches end at
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Three Neurons involved in sensory pathways
(1) First Order Neurons: Recetive field –––> Spinal cord. Synapses with –(2) Second Order Neurons: Ascend spinal cord to thalamus.(3) Third Order Neurons: Reach specific region of somatosensory cortex
94
Receptor found on postganglionic parasympathetic neuron targets (aka effector organ neurons)
Muscarinic Receptors
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Receptor found on preganglionic parasympathetic neuron targets (aka the postganglionic nerurons)
Nicotinic Cholingeric Receptors
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Receptor found on postganglionic sympathetic neuron targets (aka effector organ neurons)
Adrenergic Receptors
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Receptor found on preganglionic sympathetic neuron targets (aka the postganglionic nerurons)
Nicotinic Cholingeric Receptors
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Nerve Fibers that release norephinephrine (or epenephrine = adrenaline)
Adrenergic nerve fibers
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Receptor found on cells of the adrenal medulla
Nicotinic Cholingeric Receptors
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receptor found on endplates of motor neurons
nicotinic cholingeric receptors
101
How to number Carbons
Carbon of the Carboxyl Group (COO) = #1
102
autosomal dominant genetic defect
if you inherit the gene from one parent you can get the disease
103
Vocab:attenuate" = _____"
to reduce
104
Essential Amino Acids in Humans(and mnemonic device)
Valine Methionine Histidine Leucine Phenylalanine Threonine Isoleucine Lycine Tryptophan= Very Many Happy Little Pigs Take Iced Lemon Tea
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What does it mean for a circulatory system to be closed?
Blood doesn't freely mix with body flood
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High level summary: blood flow starting after returning from tissues
"(1) Right Atrium(2) Right Ventricle(3) Pulmonary Artery(4) Pulmonary Veins(5) Left Atrium(6) Left Ventricle(7) Aorta ––> Arteries ––> Arterioles ––> Capillaries*(where nutrient exchange occurs)(8) Venules ––> Veins ––> Superior + Inferior Vena Cava**and then back to right atrium"
107
Arteries = _________ heartVeins = ___________ heart(direction)
Arteries = AWAY from heartVeins = TO heart
108
Blood pressure measurement steps
(1) Inflate cuff so pressure > Arterial systolic pressure ---> artery collapses (stops blood flow)(2) When cuff pressure < Arterial systolic pressure, blood will flow again = "systolic pressure"-will be turbulant flow (b/c high pressure + narrow opening)(3) As relax cuff, turbulant flow will eventually disappear - instead will have laminar (smooth) flow-this is the "diastolic pressure"
109
Arteries are composed of what tissue types? Why?
Thick walls composed of smooth muscle and connective tissue (with elastin and collagen)–helps maintain pressure (and not be too high or low)
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Endothelial cells
Blood Vessel Epithelial cells
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Damage to endothelial cells = ________Lots of damage results in __________
damage = atherosclerosislots of damage = get hardening of arteries = arteriosclerosis
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Arteries are important because they represent a major area of _______ in the cardiovascular system.
RESISTANCE(thus the strong walls)
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Sphincter at the entrance to capillary bed; what it is composed of and what it does
Precapillary Sphincter–composed of smooth muscle which helps to regulate blood flow to the area
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What allows blood to flow in only one direction in a vein?
Specialized Valves in veins = prevent backflow
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Varicose beins
valve problem in veins; get backflow which increases vein pressure
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Valve between right atrium and right ventricle
Right Atroventricular ValveakaTricuspid Valve
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Valve between Right Ventricle and Pulmonary Artery
Pulmonary Valve
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Valve between left atrium and left ventricle
Left Atroventricular ValveakaMitral Valve
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Valve between left ventricle and aorta
Aortic Valve
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What happens once ventricles are filled with blood
–they contract and the AV valves close (preventing backflow) = "lub"
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What happens as blood flows out of the pulmonary artery and aorta
Pulmonary and Aortic Valves close = "dub"
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What causes the "lub" and "dub" heart noises?"
"lub" = AV valves closing"dub" = Pulmonary and Aortic valves closing
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Why don't the AV valves invert
b/c of tendinous cords = chordae tendinae which hold them in place
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What is the major pacemaker of the heart
Sinoatrial Node (SA Node)
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What happens if the SA node is damaged
AV node will take over and slow the heart rate to ~40bpm
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Where impulse travels from SA Node
SA Node ––> Atroventricular Node (AV Node) ––> Bundle of His, which causes ventricles to contract and eject blood
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Negative Feedback loop when blood pressure is too low
Stimulus: Decrease in arteriol pressure–which means less stretch on arteries––>––baroreceptors sense this and send impulses to medulla and brainstem––>–––medulla activates sympathetic nervous system––>––––Impulses sent (via sympathetic system) cause norepinephrine (or epinephrine) release at SA Node––>–––––SA Node increases heart rate––––––Increasing heart contractions–––––––Increasing Blood pressure
128
Cardiac Output
=Blood Pumped Per Minute –by each of the ventriclesin Liters/MinCardiac Output = (Stroke Volume)*(Heart Rate)liters/min = (liters/beat)*(beat/min)
129
Eqn for Poiseuille's Law
Flow = ΔPπ(R^4)/(8ηL) = (P1–P2)*π(R^4)/(8ηL)where η = viscosity ΔP = Pressure drop from 2 ends of tube R = Radius of tube L = length of tube
130
4 key takeaways from Poiseuille's Law
(1) Flow is proportional to R^4–––> VERY dependent on radius!(2) Flow is proportional to the inverse of L–––> short tubes = faster flow(3) Flow is proportional to the inverse of η–––> High viscosity = slower flow(4) ΔP is what drives blood flow in the cardiovascular system
131
How does temperature affect diffusion
Increase Temp ––> Increased Energy ––> Increased Diffusion
132
Fick's Law Eqn
J = –(D)(A)(ΔC/Δx) = –DA(Cout – Cin)/ΔxWhere J = net rate of diffusion (usually mol/s) ΔC/Δx = concentration gradient
133
Concentration of pure water
55.5 mol/L
134
What happens to the concentration of water when you add solutes? Why?
It will decrease (from 55.5 mol/L) because solute is taking up space water was taking up
135
How does the concentration of water change when adding one mol of glucose vs one mol of NaCl. Why?
One mol of NaCl will displace twice as much water – because it will ionize to Na+ and Cl– meaning that it will take up twice as much space, and decrease water's concentration by twice as much
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What is an osmol
1 mol that doesn't ionize
137
1 M NaCl soln = ______ osmol/L
2 osmol/L
138
Osmolarity
The total solute concentration of a solution
139
What is osmotic pressure (aka πosm)–and explain in terms of the semipermeable membrane experiment
The amount of pressure that stops osmosis–osmosis will occur until the added pressure (on the side of the tank with the added protein, due to the added volume) offsets the change in concentration (since water molecules will flow to the side with the higher osmolarity – the right side, through the semipermeable membrane)
140
Hydrostatic Pressure
the difference in H2O levels from one side of the semipermeable membrane to the other, Δh, which is a direct measurement of the osmotic pressure
141
Purpose of the lymphatic system
Collects excess fluid that leaks into the interstitial space from capillaries and returns it back to the circulatory system via the vena cava
142
Purpose of lymph nodes
filter out foreign particles that could cause disease
143
What happens if a lymph node is blocked?–How does this occur after heart surgery?
Edema results = increase in interstitial fluid–after heart surgery:heart can't pump blood fast enough –> backup in veins –> backup in lymphatic system––– as a result, edema occurs – particularly in swollen ankles and legs (fluid pools there due to gravity)
144
Hydrostatic pressure in the capillaries forces fluid from ________––> _________ ––> _________
Capillaries –––> Interstitial Space –––> Lymphatic Capillaries
145
Blood clotting occurs via a ______ which allows for _______.
Cascade Process allows for amplification
146
The two different pathways in blood clotting
Intrinsic Route - due to contact with some abnormal surface (e.g., "internal" damage to the blood vessel)Extrinsic Route - due to trauma of the tissue (e.g., blood vessel breaks and goes outside of the blood vessel or "external")
147
Many of the factors involved in blood clotting are called _________
serine proteases
148
Staring with Factor Xa, describe the high level cascade leading to blood clotting
(1) In presence of Factor Xa (as well as Va, an auxiliary factor); prothrombin (which ws converted from preprothrombin –––> thrombin(2) Thrombin converts: fibrinogen –––> fibrin(3) Fibrin forms the blood clot (needs transglutimase in order to be converted to crossed–linked fibrin clot in order to do the clotting)
149
How is preprothrombonin converted to prothrombin
A Carboxylase enzyme (carboxylates Glu residues)–the enzyme requires Vitamin K+ and HCO3–
150
Why is preprothrombin converted to prothrombin?
B/c Prothrombin is a good chelating agent = it has a high affinity for Ca2+ (which is essential for blood clotting)
151
How do blood platelets bind the factor necessary in the blood clotting?
The negative charge on phospholipid heads on blood platelets allows γ–carboxyglutamate residues on prothrombin to bind via Ca2+–Factor Xa also has γ–carboxyglutamate residues and also binds. Xa then cuts prothrombin releasing thrombin
152
Why fibrinogen must be converted to fibrin
fibrinogen is large and soluble with a large negative charge (which will cause repulsion)–must release some of the negative charges (as fibrinopeptides) to get to insoluble fibrin, which has a +5 central charge (in addition to still negative charged ends) –––> now can have aggregation of fibrin monomers with one another (leading to fibrin clot)
153
Soft clot vs Hard clot (in blood clotting)
Soft Clot = initial fibrin clotHard Clot = there is a cross–linking via the enzyme transglutaminase (to get cross–linked fibrin clot)
154
Once a damaged area has been repaired via blood clotting, what happens
Plasmin (a serine protease) hydrolyzes regions in fibrin clot to dissolve it into smaller fragments (removing clot)–Tissue Plasminogen Activator (TPA) converts plasminogen to plasmin
155
What is dicoumarol
Vitamin K antagonist – causes abnormal prothrombin that doesn't bind to Ca2+
156
What is warafarin
Vitamin K antagonist – causes hemorrhaging in rats and mice
157
High Level summary of how air passes down respiratory tract
(1) Oral cavity(2) Pharynx(3) Larynx(4) Trachea(5) 2 Bronchi (one to each lunch) ––– >Lungs:(6) Many bronchioles(7) MANY MANY alveoli
158
respiration
process by which oxygen is brought to the cells of tissues and CO2 is removed as a waste product
159
Composition of an alveolus2 factors leading to fast diffusion
Each alveolus consists of a single layer of epithelial cells juxtaposed to a very thin basement membrane 2 factors of fast diffusion–epithelial layer and endothelial layer of capillaries are barely separated–have millions of alveoli (large surface area)
160
Atmospheric Pressure at sea level = ______
1 atm = 760 mm Hg = 760 torr = 101,325 Pa
161
Rough makeup of Atmospheric Pressure (by molecule)
78% N221% O20.3% CO20.7% H2O
162
How to calculate partial pressures
Multiple the % of the pressure a molecule/gas makes up by the total pressure (partial pressures are INDEPENDENT of one another)
163
Why does the Partial Pressure of O2 decrease at altitude?
TOTAL pressure decreases (but O2 is still 21% of the total)
164
What does it mean if a gas is at equilibrium with a liquid
The # molecules dissolving into the liquid is the same as the # of molecules leaving the liquid ––> the partial pressure of the molecule/gas is the same in the gas phase as in the liquid
165
Total pressure of any gas is proportional to ________________.
Its concentration of molecules in the air.
166
What is the total pressure of air acting on membranes of epithelial cells in the alveoli of the lungs equal to?
The sum of the total partial pressures of all gases in the air
167
Structure of respiratory tract – how foreign objects leave the tract
Epithelial cells line lumen of passageways to bronchioles and have cilia which beat upwards.–also have mucus secreating glands.**cilia beat moving mucus and foreign objects trapped in mucus upward to oral cavity where its swallowed by reflex.
168
How does smoking affect respiratory system
–it decreases cilia activity while also decreasing the body's defense against lung infections by bacteria
169
Type of tissue that lines upper and lower respiratory tract (and how that impacts function)
Upper passageways = maintain openings by cartilage ringsLower down (bronchioles, for ex) = smooth muscle instead
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diaphragm–type of tissue–location
Skeletal muscle separating thoracic cavity and abdomen
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Pleural membranes involved in breathingWhat is in between them
Visceral Pleura = covers lungs Parietal Pleura = adheres to diaphagmin between = intrapleural space = contains watery fluid
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How does breathing occur (beginning with muscle contraction)
Rib Cage muscles contract and pull rib cage up+out while diaphragm muscles pull the diaphragm downward –––> thus enlarging thoracic cavity––> causes pleural membranes to move via suction – expanding lungs, creating subatomic pressure in alveoli ––> allowing for inspiration–when stop contracting, tissue returns to normal length and air in alveoli is forced out = expiration"
173
What would happen to the lungs without connection to visceral pleura?
lungs would collapse
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What allows for diffusion of Oxygen to capillaries and CO2 to alveoli?
Pressure differences between capillaries and alveoli
175
The greater the pressure differences, the more diffusion there is of O2 from ________ –> __________CO2 from _________ –> _________
O2: blood in capillaries –> tissue cellsCO2: tissue cells –> blood in capillaries
176
How is oxygen carried in the blood
Mostly through hemoglobin; a little through diffusion
177
hemoglobin
transport protein in red blood cells – transports O2
178
Structure of hemoglobin
quaternary structure–has 4 polypeptide subunits––each has a heme group with a Fe2+ in the center––in total can bind 4 O2
179
What happens to O2 solubility in blood due to hemoglobin?
When hemoglobin takes up O2, more O2 can leave gas phase in alveoli and enter the blood – thus increasing O2 solubility in blood
180
How saturated is hemoglobin in the capillaries?–How much of this O2 does hemoglobin give up to tissues?
98% saturated with O2 in capillaries–only gives up ~25% to tissues
181
what happens to the O2 dissociation curve of hemoglobin when pH is decreased?–one example of when this cold occur
Curve shifts down and right–ex: exercise
182
–what happens to the O2 dissociation curve of hemoglobin when 2,3–BPG (a byproduct of glycolysis) binds to hemoglobin?–one example of when this cold occur
Curve shifts down and right–ex: O2 deprivation
183
What happens when hemoglobin O2 dissociation curve shifts?
Shifts down and right = causes hemoglobin to release more O2 to tissues at the same PO2
184
How is CO2 carried in the blood?
(1) 70% – in HCO3– form(2) 20% – on hemoglobin(3) 10% – dissociated in plasma and red blood cells
185
How does CO2/HCO3– conversion occur in tissues
(1) CO2 diffuses into RBC where it is converted to H2CO3 via carbonic anhydrase(2) H2CO3 ionizes to H+ and HCO3–(3) HCO3– diffuses into blood plasma and is carried to capillaries of lungs by circulatory system
186
How does CO2/HCO3– conversion occur in the lungs?
(1) HCO3– diffuses into RBC where it combines with H+ and becomes H2CO3(2) H2CO3 is converted to CO2 via carbonic anhydrase(3) CO2 diffuses into blood plasma and then diffuses into capillaries and then to the alveoli
187
What part of the brain coordinates breathing
Brainstem – particularly medulla and pons
188
How do medulla and pons coordinate breathing
Δ[H+] and Δ[CO2] –––> affect chemosensitive areas of medulla and Δ[O2] is sensed by chemoreceptors of cartoid arteries and aorta arch–––>–transmit signals to brainstem*nerve impulses from medulla and pons cause respiratory muscles to contract
189
bronchioles are innervated by ___________ nerves
Parasympathetic
190
What is asthma
hypersensitivity to airborne antigens –––> spasm and constrict smooth muscles of bronchioles
191
The total cross sectional area of ________ is the largest of all types of vessels in the cardiovascular system
all the capillaries
192
_______ regulate the flow of blood throughout the body
areterioles
193
Blood pressure has the highest velocity and the highest pressure when __________
After exiting the left ventricle
194
______________ measures turbulant flow.
Reynold's Number.Usually turbulant when Re > 2000
195
Reynold's Number Equation
Re = vdp / nwhere v = velocity d = vessel diameter p = density n = viscosity
196
Which walls are stronger: arterial walls or vein wallsWhich are more distensible
ARTERIAL walls are strongerthus VEIN walls are more distensible
197
Which walls are less distensible – systemic artery walls or pulmonary artery walls?Why?
Systemic Artery WallsB/c they are under more pressure and thus less distensible
198
what is the effect of blood centrifugation?
Separates plasma and Red Blood Cells –with a buffy coat in between (made up of WBC and platelets)
199
What is the ames test?
Ames test for mutagens:Mix suspected mutagen (a chemical) with bacteria (as well as, for example, liver extract), incubate, and see if many mutated colonies appear. If they do, the suspected mutagen is in fact a mutagen.
200
How many rings do purines and pyrimidines have?
Purines have 2 ringsPyrimidines have 1 ring
201
What about the SA node allows for it to be a pacemaker
Gradual depolarization – called pacemaker potential – which brings the membrane potential to threshold, when an action potential can occur
202
Alkane and alkene chemical formulas
Alkane = CnH2n+2Alkene = CnH2n
203
Phosphorylation = the addition of _______
Phosphate: PO4 3–
204
Acetylation = the addition of
Acetate: C2H3O2–
205
Carboxyl Group (chemical formula)
COOH
206
The heart rate is controlled by ____
Medulla Oblongata
207
Where does Transcription of mRNA from DNA occur?
the nucleus
208
Where does Protein Translation occur? Where does the protein go next?
- Occurs in the Endoplasmic Reticulum
- Leaves the ER in vesicles and is transported to the Golgi Apparatus for post-translational modification before being packaged so that can leave the cell
209
Which cellular organism do eukaryotes have but viruses, bacteria, and archae lack
Golgi Apparatus
210
What type of enzyme is responsible for the cleavage of phosphate bonds using water to remove a molecule of inorganic phosphate?
phosphatases
211
What will happen if you were to put mouse antibodies in a human?
The human would produce antibodies against the mouse antibodies (b/c it would recognize it as foreign)
212
If a father is non-diseased for a recessive-X-linked-disease, what is true (or could be true) about his daughter?
She must NECESSARILY by non-diseased
213
If a mother is homozygous for a recessive X-linked gene, what is true (or could be true) about her son?
He must NECESSARILY by affected
214
What are introns?
region of DNA that is removed during the processing of mRNA (e.g., AFTER transcription)
215
Where does transcription occur in prokaryotes
In the cytoplasm;
so ribosomes can bind and begin translation before transcription is complete
216
What is nondisjunction?
-The failure of homologous daughter chromosomes to separate during anaphase I of meiosis
OR
-The failure of sister chromosomes to separate during anaphase II of meiosis
217
Mistranslation of codons will likely increase ______ (in proteins)
protein misfolding
218
"high affinity transport"
vs
"high transport capacity"
"High affinity transport" = transporter has a high affinity for a particular substrate (so will bind even when have low [substrate])
"High transport capacity" = transporter can transport a lot of the substrate (so if have high [substrate], the transporter will be able to transport a lot])
219
Kt depends on what (and not on what)?
| enzyme kinematics
-Is a property of the transport protein itself. Does NOT depend on the concentration of the transport protein.
220
Kt depends on what (and not on what)?
| enzyme kinematics
-Is a property of the transport protein itself. Does NOT depend on the concentration of the transport protein.
221
What is the Michaelis Menton Equation
V(0) = V(max)*[S} // K(m) + [S]
222
What is the Lineweaver Burk Plot eqn?
- slope
- y-intercept
- x-intercept
1 // V[0] = (K(m)/V(max))*(1/[S]) + 1/V(max)
(y = mx + b)
```
y-intercept = 1/V(max)
slope = K(m) / V(max)
x-intercept = -1/Km
```
223
Compare the three types of enzyme inhibitors
(1) Competitive inhibitor:
- binds to free E
- increases Km, Vmax is same (so in LW plot, slope increases, but y-int is same)
(2) Uncompetitive inhibitor:
- binds to ES complex
- decreases Vmax (in LW plot, slope is the SAME, but y-int increases)
(3) Noncompetitive ("mixed") inhibitor:
- binds to ES or free E
- Vmax decreases, Km increases (in LW plot, slope increases, and y-int increases also)
224
Kcat
= Vmax / [E]t
-is equal to the turnover # (# of rxns / s)
225
Calculating enzyme catalytic efficiency
catalytic efficiency = Kcat / Km
226
What is Km equal to
(1/2) Vmax
227
cytochrome c
A heme protein that only cycles between a ferrous and ferric state during oxidative phosphorylation ---> thus a 1-electron carrier
228
What isomeric form of amino acids are used to form proteins during ribosomal protein synthesis
ONLY the L-isomers
229
How many ATP molecules are formed per molecule of glucose....
- under aerobic conditions
- under anaerobic conditions
- aerobic = use cellular respiration; 38 ATP produced
| - anaerobic = use fermentation; 2 ATP produced
230
What are the 3 types of protein filaments that make up the cytoskeleton
(1) microfilaments (aka actoin filaments)
(2) Intermediate filaments
(3) Microtubules
231
What type of filaments are actin filaments?
Microfilaments
232
Path of blood flow after heart and then back to heart
- Heart -->
- Aorta -->
- Arteries -->
- Arterioles -->
- Capillaries (and out to tissues) -->
- Venules -->
- Veins -->
- Inferior or superior vena cava -->
- Heart
233
What would happen if someone had fewer visual pigments?
Fewer signals would be sent to the brain
234
How many visual pigments are there (what are they?)
3, which absorb
- red
- green
- or blue light
235
What does Brown Adipose Tissue contain a large number of (and what does it do)
Large number of mitochondria that generate heat during thermogenesis
236
In the absence of oxygen, what happens to pyruvate (instead of ___)?
-Pyruvate is converted into lactate in the cytoplasm and is NOT transported to the mitochondria to be converted to acetyl-CoA
237
If a genome were to be 23% Adenine, what would it be of G, C, and T
23% T
(100% - 2*23%) = 54%; 54%/2 = 26%, so
27% G
27% C
238
Basic structure of fatty acids
- Carboxylic head group and
| - a hydrocarbon tail
239
Systemic veins carry _____ levels of CO2 and systemic arteries carry ______ levels of CO2
---what does this say about HCO3- conc?
- Veins = HIGH CO2
- Arteries = LOW CO2
-same for HCO3-
240
How do gases enter and exit the RBC
Through diffusion across the RBC plasma membrane.
241
What is a benefit of RBCs not containing nuclei (why don't they contain nuclei)?
- More room for hemoglobin, so more oxygen can be taken up
| - RBCs push out their nuclei
242
What is a lysosome
an organelle in the cytoplasm of eukaryotic cells containing degradative enzymes enclosed in a membrane.
243
What is the pathway of endocytosis?
Early endosomes --> late endosomes --> lysosomes (to degrade the material)
-can have vesicles pass between the Golgi and endosomes in both directions
244
Helices are a type of ____ structure
Secondary strcuture
245
What is a lysozyme
an enzyme that degrades the wall of bacteria (causes lysis)
246
The LOWER the Kd value, the _____ the affinity for the antibody
HIGHER
247
What is Kd for atibodies?
The equilibrium dissociation constant
- a ratio of koff / kon between the antibody and its antigen
- Kd and affinity are inversely related
248
What do proteases do?
Enzymes that perform protein catabolism by hydrolysis of peptide bonds
249
What is an operon?
A functioning unit of genomic DNA containing a cluster of genes under the control of a single promoter
250
Most of the lining of the mouth is derived from what type of germ layer?
Invagination of ectoderm
251
Most epithelial tissue inside the body is derived from what germ layer?
Endoderm
252
What type of tissue makes up the bronchi, bladder, stomach, etc.
Epithelial tissue
253
what is chelation
a type of bonding of ions and molecules to metal ions (such as Ca2+)
254
Blood contains many more (WBC/RBC) than (WBC/RBC)
Many more RBCs than WBCs
255
How is turbulent flow measured?
Using Reynold's # (usually Turbulent when Re>2000).
Re = vd/(n/p)
where v = velocity, d = vessel diameter, n = viscosity, and p (row) = density
256
Structure of purines vs pyrimidines
purines have 2 rings, and pyrimidines have 1 ring
257
Number of Oxygens on the nitrogenous bases
G & C = each have 1 oxygen
T (or U) = 2 oxygens
A = 0 oxygens
258
Chemical structure of
| -alkanes vs. alkenes
Alkanes (non-cyclical) = CnH(2n+2)
| Alkenes (non-cyclical) = CnH(2n)
259
Cellulose
glucose polysaccharide found in plant walls
260
Cellulase
enzyme that hydrolyzes cellulose to release glucose
| -humans don't have cellulase so can't digest cellulose
261
Starch and glycogen
Important polysaccharides in nature
262
Amylases
hydrolyze starch and glycogen to release glucose
263
What type of animals can digest cellulose
Animals with a rumen - which contains microorganisms that secrete cellulase (an example of a symbiotic relationship)
264
Proteases
enzymes that hydrolyze proteins to their constituent amino acids
265
enzymes that hydrolyze proteins to their constituent amino acids
proteases
266
lipases
enzymes that hydrolyze fat (aka triglycerides; which is stored in adipocytes) into fatty acids + glycerol
267
enzymes that hydrolyze fat (aka triglycerides; which is stored in adipocytes) into fatty acids + glycerol
lipases
268
where are triacylglycerides stored?
adipocytes
269
Vitamins
Molecules needed in only small amounts, but are essnetial
270
Essential amino acids
the 9 (of the 20 basic amino acids) that humans need to obtain in our diet (the rest humans can synthesize
271
5 general components to a complete diet
(1) Carbohydrates (in sugar form)
(2) Fats
(3) Protein
(4) Vitamins
(5) Minerals
272
Inner layer of the small intestine
- made up of
- features
- epithelial cells
- convulated for increased surface are digestion
- external exocrine glands (from pancreas/liver/etc.) are scattered here)
- also ave endocrine cells that release hormones
273
How does the lower GI tract contract as food passes through?
- Smooth muscle (surrounding the epithelial cells) contracts in peristaltic waves - controlled by parasympathetic system and hormones)
- fast due to gap junctions in circular and longitudinal muscles of GI tract
274
What enables quick peristaltic action in the lower GI tract
electrical continuity imposed by the gap junctions in the circular and longitudinal muscles of the GI tract
275
salavary amylase
begins digestion
| -digests starch and glycogen (carbohydrates)
276
Epiglottis
tissue flap covering larynx opening so that food doesn't enter, and instead food enters esophagus and then goes to stomach
277
the swallowing reflex is controlled by the _____
medulla
278
What contracts to prevent regurgitation of food back to the esophagus?
gastroesophageal sphincter
279
Functions of the stomach
(1) Break food down to smaller particles
| 2) detoxify food (by acidic secretions
280
What are the 4 major types of stomach secretions? (and what type of cells secrete them)
(1) Mucus = (by surface cells); protects lining of stomach and lubricates the food
(2) Gastrin = (by endocrine cells); secreted in response to protein entering the stomach; stimulates the secretion of pepsinogen and HCl
(3) HCl = (by parietal cells) pH ~ 1; converts pepsinogen -> pepsin. Once pepsin is formed, pepsin can also convert pepsinogen -> pepsin
(4) pepsinogen = (by chief cells); inactive form of the peptidase enzyme pepsin
281
What stimulates secretion of HCl and pepsinogen
gastrin
282
What do chief and parietal cells do?
Chief Cells --> Secrete pepsinogen (in stomach)
| Parietal Cells --> Secrete HCl (in stomach), and also intrinsic factor (a glycoprotein)
283
intrinsic factor
- A glycoprotein secreted by parietal cells in the stomach
- complexes with Vitamin B12 and is then absorbed by intestinal epithelial cells and transported by bloodstream (without intrinsic factor, would be deficient in Vitamin B12 - which is necessary for RBC formation)
284
Why do ulcers occur in the stomach?
-if too much acid is secreted into the stomach
285
histamine and the stomach
histamine stimulates the release of HCl into the stomach.
286
Cimetidine drug
inhibits histamine from binding to parietal cells (in the stomach), thus inhibiting their release of HCl into the lumen of the stomach
287
Where does the majority of digestion occur?
90% of digestion occurs in the small intestines
288
Acidity of small intestine?
Small intestine neutralizaes the acid secreted by the stomach
289
Cholecystokinin (CCK)
- Small intestine distension causes its release
| - diffuses through bloodstream to pancreas, where it causes pancreas to release digestive enzymes
290
Secretin
a hormone released by the small intestine in response to entering chyme from the stomach
-transported by bloodstream to pancreas - causing it to release bicarbonate ion and other fluid
291
CCK and Secretin
- why released
- effects
CCK:
- released when small intestine distends
- causes pancreas to release digestive enzymes
Secretin:
- released when chyme enters small intestine from stomach
- causes pancreas to release bicarbonate ion and other fluid
292
acini
- structures in the pancreas
- secrete fluid into small intestine that has a high bicarbonate content ---> the bicarbonate ions will combine with HCl to produce carbonic acid, which is converted to CO2 and H2O --> will cause the pH in the small intestines to increase
293
Main secretions from pancreas
- insulin and glucagon (from endocrine cells)
| - Bicarbonate ion (from acini strucutres)
294
main function of liver
-synthesizes bile (which is stored in the gallbladder)
295
bile
- where synthesized
- where stored
- synthesized in liver
| - store in gallbladder
296
Effects of presence of fat in small intestines
- causes release of CCK by the small intestine
- CCK release causes gallbladder to contract and sphincter of oddi to relax ---> resulting in bile passing into lumen of small intestine
297
What is the major pigment in bile (and what is it)
bilirubin - a breakdown product of hemoglobin
298
What are bile salts
contained in bile; important in fat digestion and absorption
299
Process of bile release (and what it does afterwards)
- Bile is released from gallbladder and passes through a duct that joins with the pancreatic duct through the sphincter of odd, and empties in the small intestine
- there it emulsifies fat and helps epithelial cells absorb fat
300
sphincter of oddi
a muscular valve that controls the flow of digestive juices between the liver/pancreas and the small intestine
301
Transport proteins in the small intestine
- where located
- function
- located on apical (lumen side) and basolateral (blood side) regions of the epithelial cells in the small intestine
- allow the absorption of many compounds, including Na+, glucose, minerals, etc.
302
Cholera Toxin
caused by massive loss of fluid by diarrhea
303
osmosis and the small intestines
Water diffuses into the lumen through osmosis
304
Main function of large intestine
- absorb most of water ad ions left in chyme as it passes from the small intestine
- what's not absorbed passes in feces
305
Chylomicrons
- formation of
- where they go
- fatty acids and glycerol diffuse into intestinal epithelial cells where they are resynthesized into triglycerides - and aggregate into chylomicron structures
- chylomicrons are released into the basolateral membrane. They enter into lymph and are transported to the veins and eventually the tissues.
306
Where is the water in the human body distributed
- 2/3 of water is in cells (intracellular fluid)
| - 1/3 of water is in the interstitial space (extracellular fluid)
307
How is water lost in the human body
- integuement (the skin, via evaporation)
- GI Tract
- lungs
- urinary system
308
The water lost from the body exactly matches _______
the water gained by the body by fluid consumption and regulation at the level of the kidneys
309
osmoconformers
Organisms that can change internal ionic concentration of its body fluids to meet that of surrounding environment
310
osmoregulators
Organisms that DON'T change their internal ionic concentration to meet that of their environment
311
Three main functions of vertebrate kidneys
(1) Filtration
(2) Reabsorption
(3) Excretion
312
How does filtration occur in the kidney (high level)
through the nephron: the functional unit of kidney. Which consists of a:
- glomerulus (collection of capillaries that receives blood from an artery terminating at the renal system
- bowman's capsule
- tubular system
*blood is pumped into the glomerulus by the hydrostatic pressure of the heart, and that pressure forces the blood through the capillary walls and into Bowman's capsule. (the cell-free ultra-filtrate in Bowman's capsule lacks many of the plasma proteins found in blood
313
How does reabsorption occur in the kidney (high level)
Through many of the epithelial cells that line the tubular lumen of the nephron
- cilia of the epithelial cells propel filtrate through renal tubes
* glucose, small proteins, amino acids, salts, bicarbonate ions, and water and reabsorbed by the tubes and transported back to the blood
* epithelial cells can also secrete protons, K+, urea, uric acid, and ammonia
314
Where does blood enter the kidney from
-Blood from the descending aorta enters the renal artery and eventually enters the glomeruli
315
Where does blood leave the kidney from?
-by the renal vein, which empties into the inferior vena cava.
316
Where does urine exit the kidney from (and where does it go)
-the ureter transports urine to the bladder, where it exits via the urethra
317
Cortex vs. Medulla (or kidney)
- Glomeruli and bowman's capsule are in the cortex, so it is granular in appearance
- medulla is striated and contains the loop of henle and the collecting ducts (which collect urine and empty into renal pelvis of kidney and then the ureter)
318
As renal artery enters the kidney, what happens to it?
It branches and becomes the afferent arterioles - which enter bowman's capsule and form the glomerulus
319
What leaves the glomerulus and forms capillaries surrounding renal tubules?
- the efferent arteriole
- the blood that leaves the capillary network does so through a venule which empties into the renal vein that leaves the kidney
320
What extends from Bowman's capsule (in order)?
(1) Proximal convoluted tubule (PCT)
(2) Loop of Henle
(3) Distal Convoluted Tubule (DCT)
(4) Collecting Duct
321
What is the osmolarity of filtrate in Bowman's Capsule (and what is it equivalent to)?
~ 300 milliosomols = that of filtrate in PCT = that of plasma
322
What is dilute urine vs. concentrated urine
Dilute urine = osmolarity < that of filtrate in Bowman's capsule, PCT, and plasma (<300 momols)
Concentrated urine = >300 mosmol
323
What is the PCT, and what are its functions and features
= Obligatory section of nephron (b/c it is where ~65% of all reabsorption and secretion occurs)
- epithelial cells are very metabolically active --> so have active transport
- many reabsorption methods require Na+
- All glucose, small proteins, Amino Acids, and Vitamins are reabsorbed here, as are most ions and water
- little regulation occurs here
324
Segments of Loop of Henle
(1) Thin Descending
(2) Thin Ascending
(3) Thick Ascending
325
Function: Thin descending loop of henle
Very permeable to H2O, but only relatively permeable to ions and molecules
326
Function: thin ascending loop of henle
More permeable to urea, less permeable to H2O
327
Function: thick ascending loop of henle
- Actively transports ions to interstitial fluid from lumen of loop
- impermeable to urea and water (so filtrate is becoming less dilute)
328
High level: ion and water concentration in kidney medulla (due to loop of Henle)
- loop of henle makes the medulla very SALTY.
- the ascending loop pumps out the salts
- the descending loop, which is permeable to water - has water diffuse out since the medulla is salty ---> in this way, the saltiness allows water to leave the loop into the medulla
329
Distal Convoluted Tubule:
| -segments and functions of each segment
(1) segment close to loop -->
- impermeable to urea and H2O, but permeable to ions (Na+, etc.) --> filtrate becoming more dilute
(2) segment close to collecting duct & portion of collecting duct in cortical region of kidney -->
- impermeable to urea
- sensitive to hormone aldosterone and ADH
330
aldosterone
- secreted in cortex by adrenal glands
- regulates Na+ concentration
- increased aldosterone --> Na+ is reabsorbed by epithelial cells (and K+ is simultaneously pumped into nephron lumen)
331
Antidiuretic Hormone (ADH)
- Produced by hypothalamus and released by posterior pituitary
- regulates water consumption
- increases ADH ---> water reabsorbed from epithelial cells in collecting duct and passed into interstitial Fluid (concentrates urine, by removing water from the urine)
332
Homeostatic maintenance of Na+ concentration
-decreased Na+ ==> cells in adrenal cortex release aldosterone ==> causes DCT and collecting duct to reabsorb Na+
333
Homeostatic water maintenance
-decrease in plasma volume ==> decrease in Blood pressure, which is detected by osmoreceptors ==> hypothalamus synthesizes and transmits ADH to posterior pituitary where it is released to blood ==> ADH causes DCT and collecting duct to reabsorb H2O
334
Effects of alcohol use on water homeostasis
-Alcohol inhibits ADH
335
Main source of nitrogenous waste in the bod
Proteins and nucleic acids
336
3 Ways to remove nitrogen waste (as):
(1) Ammonia
(2) Urea
(3) Uric Acid
337
Ammonia vs. Urea vs. Uric Acid
Ammonia
-toxic & soluble
-in fish, glutamine is converted to ammonia which combines with a proton and is excreted (mammals can also excrete ammonium)
______________
Urea
-less toxic & soluble
-exreted by mammals (in urine; is a glutamine byproduct)
_______________
Uric Acid
-toxix & insoluble
-excreted by birds and reptiles (ammonia is converted to uric acid)
338
Normal pH of body
~7.4
339
How is body pH regulated
through buffering system --> H+ bound to buffer (such as HCO3-)
340
Cholera Toxin
Acute intestinal infection transmitted in contaminated food/water
-leads to rapid fluid loss
341
What type of hormone is norepinephrine
An amine hormone
| -specifically, a catecholamine
342
What type of hormone is epinephrine
An amine hormone
| -specifically, a catecholamine
343
What type of hormone is dopamine
An amine hormone
| -specifcally a catecholamine
344
What type of hormone is aldosterone?
A steroid hormone
- more specifically, a corticosteroid
- even more specifically, a mineralocorticoid
345
What type of hormone is insulin?
a peptide hormone
346
What type of hormone is glucagon?
A peptide hormone
347
What type of hormone is cortisol?
A steroid homone
- more specifically, a corticosteroid
- even more specifically, a glucocorticoid
348
Two subroups of steroid hormones (and the five subtypes that fit into the two subgroups)
(1) Corticosteroids
- Glucocorticoids
- Mineralocorticoids
(2) Sex Steroids
- Androgens (such as testosterone)
- Estrogens
- Progesterone
349
Hypertonic solution
Having a higher osmotic pressure than a particular fluid (typically body fluid or intracellular fluid)
350
Water moves from a region of _____ osmotic pressure to a region of _____ osmotic pressure
From low ----> high
351
What hormone is responsible for taking fat from the vascular system and facilitating its uptake into adipose tissue
Insulin
352
Parietal cells secrete ______ into _____ and also _____ into _______.
secrete H+ into the intestinal lumen and bicarbonate into the blood
353
pancreatic cells release bicarbonate into ______ along with _____ into _____
Bicarbonate into the intestinal lumen along with H+ into the blood
354
GnRH
Gondadatropin releasing hormone, released by the hypothalamus, causes the anterior pituitary to release gonadatropins (which go to the gonads)
355
Gonadatropins
- what
- released by what (and why)
- cause
- Luteinizing Hormone (LH) & Follicle stiulating hormones (FSH)
- released by the anterior pituitary, caused by release of GnRH by the hypothalamus
- stimulate the gonads - to produce steroid hormones and germ cells (ova or spermatazoa)
356
seminiferous tubules
series of convoluted tubules in testes
| -where sperm is produced
357
where are sperm produced (and why?)
in Testes - which lies in scrotum, which is outside of the body cavity
-b/c sperm formation requires a lower temp (than body temp)
358
What is the process between spermatagonia and spermatazoa
starts at basement membrane of semineferous tubules _____
(1) Spermatagonia 1*(2n) ---mitosis--->
(2) Primary spermatocytes 1*(2n) ----meiosis I-->
(3) Secondary spermatocytes 2*(1n) ---meisosis II-->
(4) Spermatids 4*(1n) --transformation-->
(5) Spermatazoa 4*(1n)
359
What are the primary things occurring in the testes?
____
-cells related to each thing
(1) Sperm is produced (in semineferous tubules) [by spermatogenic cells]
(2) Leydig Cells synthesize testosterone (outside of tubules)
(3) Sertoli cells promote spermatagenesis and produce inhibin protein hormone (in tubules); sertoli cells are in constant contact with spermatagonic cells
360
Cytoplasmic Bridges in the semineferous tubules
Connect the spermatids
361
Acrosome
- tip of sperm
| - has digestive enzymes that help gain access to egg interior after fertilization
362
Where are the DNA and mitochondria of the sperm?
- DNA = in head of sperm
| - mitochondria = in midsection
363
function of mitochondria in sperm
-provides energy to tail so can swim
364
How is testosterone formed
Leydic cells convert cholesterol ---> testosterone
365
Testosterone's 2 main roles
(1) Can move into target tissues
(2) Can diffuse into Sertoli cells - where it binds to a receptor and is converted to dHT (dihydrotestosterone), which diffuses into nucleus of sertoli cells and instructs DNA to produce RNA (which affect spermatagoneic cells)
366
Function of LH in males
-binds to receptor on Leydig Cell, producing secondary signal ---> increases conversion of cholesterol to testosterone
367
FSH Function in males
-Binds to receptor on Sertoli Cell and induces secondary response --> helps convert testosterone to dHT (and also induces the synthesis of the receptors)
368
How is GnRH inhibited (in males)?
-Testosterone inhibits GnRH
369
How is LH inhibited (in males)
-Testosterone inhibits LH
370
How is FSH inhibited (in males)
-Inhibit inhibits FSH
371
Sperm Travel
```
SEVEN UP
(1) Seminiferous Tubules
(2) Epididymus
(3) Vans Deferens
(4) Ejaculatory Duct
N=nothing
(5) Urethra
(6) Penis
```
372
what makes up semen?
Small part sperm, the rest is secreted by:
-seminal vesicles
-prostate gland
-bulbourethral glands
(fructose, vitamins, zinc bicarb, prostagalandins, mucus,, etc.)
373
How long can sperm live in the vagina?
~48 hours
374
Sperm travel in females
(1) Vagina ->
(2) Oviduct (aka fallopian tubes) = site of fertilization.
Once have a fertilized egg:
(3) Egg implants in uterus - in uterine lining - ~1 wk after ovulation. Continues to grouw here until delivery
375
What is the egg called once it implants in the uterus
a blastocyst
376
Oogenesis vs spermatogenesis
| 2 main differences
(1) spermatogenesis yields 4 identical sperm, oogenesis yields 1 egg (and 2 polar bodies)
(2) Mitosis ceases within 2-3 months of fetal development in females --> so females are born with all the primary oocytes she'll ever have (males continue producing primary spermatocytes)
377
What happens to the primary oocytes
Most degrade --> called atresia
| -the rest will mature
378
Oogenesis (beginning to end)
(1) Oogonia 1*(2n) --mitosis-->
(2) Primary Oocyte 1*(2n) --Meiosis I---arrested in prophase, monthly with a surge of LH continues-->
(3) (first polar body) + Secondary Oocyte 1*(1n) ---Meiosis II---arrested in anaphase, only after fertilization continues--->
(4) (second polar body) + zygote 1*(2n)
379
Primary follicle
a primary oocyte surrounded by a layer of follicle cells. Eventually 1 ill start to develop
380
follicular phase
- what it is
- how long
pre-ovulation, when primary oocyte matures
| -lasts up to the ~14th day of woman's monthly cycle
381
Zona pellucida
membrane surrounding primary oocyte - is surrounded by more follicle cells called granulosa cells and thecal cells
382
Theca Cells are the female equivalent of _____, and granulosa cells are the female equivalent of _____.
```
Theca = leydig
Granulosa = Sertoli
```
383
What are the main events of the folliclar phase
(1) Fluid builds up in the primary follice, forming the antrium
(2) LH surge causes meiosis I - forming secondary oocyte - and production of enzymes that break down membrane on primary follicle
(3) after secondary oocyte is released, ovulation occurs (the beginning of the luteal phase)
384
Luteal phase
| -what and when
After 14th day of monthly cycle, starts at ovulation and lasts until menstrual flow.
385
Main events of luteal phase
(1) Begins at ovulation
(2) Leftover follicle is transformed into corpus luteum which produces estrogen and progesterone
(3) Corpus luteum degenerates if no fertilization and cycle starts again (thus Luteal phase ends at the beginning of menstrual flow)
386
LH and FSH and estrogen levels during woman's monthy cycle
(1) LH levels are flat until LH surge just before ovulation
(2) LH Surge also has an FSH surge with it (although not as much)
(3) estrogen surges before ovulation and then a little afterwards
(4) the increase in estrogen will lead to an increase in LH
387
What do theca cells do?
Convert cholesterol to testosterone in females
388
Testosterone in females?
- synthesized by theca cells from cholesterol
| - diffuses into follicle cells and is converted to estrogen, which helps to develop the primary follicle
389
Effect of follicle cell proliferation on estrogen
- follicle cells produce estrogen,
- just after being converted to the corpus luteum, they lose the ability to produce estrogen briefly - but long enough so that LH levels decrease
- the corpus luteum becomes an endocrine gland then and synthesizes estrogen and progesterone
390
Estrogen and FSH effects on eachother
-Estrogen inhibits FSH (which usually stimulates follicle production).
391
Effect of estrogen and progesterone on LH and FSH
- Estrogen has positive feedback on LH until after the LH surge (but a negative feedback on FSH)
- After the LH surge, will lose the positive feedback.
- The corpus luteum will then be produced, and start producing estrogen and progesterone
- Estrogen and progesterone IN COMBINATION exhibit negative feedback on both FSH and LH (and GnRH) -- so primary follicle won't develop as long as corpus luteum is producing estrogen and progesterone
392
Phases of pregnancy from acrosome digesting secondary oocyte membrane ---> placenta formation
(1) acrosome digests membrane of secondary oocyte
(2) Zona pellucida receptor sites for sperm prevents cross-species fermentation
(3) Nucleus (and only nucleus) of sperm enters secondary oocyte
(4) Zona pellucida changes and prevents other sperm entry
(5) Secondary oocyte undergoes Meiosis II
(6) Nucleus of sperm and egg fuse to form zygote
(7) Zygote attaches to uterine lining in ~7 days (now called blastocyst)
(8) Placenta begins to form at implantation
393
What prevents cross-species fermentation
Zona-pelluicida receptor sites for sperm
394
blastocyst
small ball of cells with central fluid filled cavity
395
What happens during the first 3 months of pregnancy
- placenta secretes chorionic gonadatropin, CG, which stimulates the Corpus Luteum
- Corpus Luteum secretes estrogen and progesterone (which inhibits the Anterior pituitary, so no new primary follicles, ovulation, or menstruation)
- Anterior Pituitary releases prolactin, stimulating mammalary glands
- Placenta secretes chorionic somatomammotropin (CS) which stimulates mammary glands also
396
What in the first 3 months of pregnancy stimulates mammary glands
- prolactin (from anterior pituitary)
| - chorionic somatomammotropin (from placenta)
397
What happens in the last 6 months of pregnancy
- chorionic gonadatropin is no longer made - so the corpus luteum breaks down
- instead, placenta synthesizes estrogen and progesterone (and makes much more than did the Corpus Luteum)
398
6 Main stages of development
(1) Fertilization
(2) Cleavage
(3) Gastrulation
(4) Neurulation
(5) Neural Crest Formation
399
6 Main stages of development:
| (1) Fertilization
Union of male and female gametes to form zygote
400
6 main stages of development:
| (2) Cleavage
Zygote rapidly divides into many cells wihtout changing overall size
401
6 Main stages of development
| (3) Gastrulation
Cells migrate to form 3 germ layers
402
6 Main stages of development
| (4) Neurulation
Begin to form nervous system (first organ system to begin to differentiate)
403
6 Main stages of development
| (5) Neural crest formation
Neural crest cells help form parts of nervous system, skull, and sensory organs
404
6 Main stages of development
| (6) Organogenesis
Different organs in body are formed
405
Unfertilized frog egg has ___ poles (what are they)
2:
-animal pole = upper, mainly cytoplasm
___
-vegetal pole = lower; contains the yolk
406
What happens once sperm enters frog egg
Gray Crescent forms opposite site of sperm entry
407
Gray Crescent
- where located
- what ends up here
In frog egg, forms once sperm enters - forms opposite site of sperm entry
- located on dorsal side
- eventually where will have spinal cord and brain
- middle of gray crescent defines body midline
408
Where does the first cleave occur in frog zygotes?
-along midline (so bisecting gray crescent)
409
Blastomeres
individual cells involved in zygote cleavage
410
morula
solid ball of cells formed at the 32 cell stage of frog development, during cleavage
411
Cleavage stage of development is characterized by _____
Cell division that increases a zygote's mass, with its overall size remaining the same.
412
Blastula
Forms during frog gastrulation (after morula forms)
| -a hallow ball of cells, with a fluid filled cavity called a blastocoel
413
The events leading up to which phase of development vary widely among animals (but this phase is common to all of them)?
gastrulation
414
Phases of gastrulation in frogs
(1) Blastopore opens (near gray crescent)
(2) Cells from animal pole migrate in and form second layer of cells below outer layer (blastocoel is reduced in size and ultimately eliminated)
(3) Archenteron (a cavity) forms in place of blastocoel (embryo is now called a gastrula)
(4) Outer cell layer invaginates to form 2 cell layers: ectoderm (outer layer) and endoderm (inner layer); mesoderm will later form in between
415
Developmental fates of the ectoderm, endoderm, and mesoderm
ECTODERM = skin, brain, and nervous system
________
ENDODERM = digestive and respiratory tracts (inner linings), and major glands (liver, pancreas, etc.)
________
MESODERM = notochord, heart, skeleton, muscle
416
Neural Plate
Above the notochord, the neural plate is a mass of ECTODERM cells that will fold in on itself to form the neural groove (with the edges of the folding fusing to form the neural tube - within which will be the spine)
417
Primordium
Neural plate tissue (ectodermal)
418
Neurula
name for the embryo during neurulation
419
Neural crest cells
Ectodermal cells that don't fuse to become the neurol tube, and instead move to side and begin to functionalize
-eventually they become sensory cells, adrenal medulla, and more
420
More hormone released by adrenal medulla
adrenaline - which prepares animal to fight
| -increases blood sugar, hr and bp
421
Somites
Segments of mesodermal tissue that form during organogenesis
| -will eventually give rise to vertebrae and connective tissue and muscle
422
Morphogenesis
Last phase of development for a frog
- tadpole changes to sexually active organism
- grows limbs, develops lungs, and loses tail and gills
423
What triggers frog tadpole to grow limbs, develop lungs, and lose tail and gills
-the release of thyroxin from the thyroid gland
424
Indirect vs direct development
Indirect = post-embroynic organism left on its own
--
Direct = care is given to post-embryonic organism by mother
425
2 classes of interaction associated with differentiation
(1) intracellular interactions = interactions between components within the cells themselves (usually result in setting up a prepattern)
(2) intercellular interactions = interactions between cells , usually undergo developmental induction
426
what establishes direction in an egg
sperm entry
427
Hans Speemann Gray Crescent Experiment
* showed development of gray crescent*
- took 2 eggs and tied string around - 1 bisected gray crescent, and 1 egg had all gray crescent on one side
- when bisected, 2 embryos formed from each side
- when all of the gray crescent was on one side --> 1 embryo forms (and once mass of cells formed)
428
Dorsal lip in frog
Area where cells from animal pole begin to invaginate into the blastula --> leads to formation of blastopore and development of archenteron
429
Hilde Mangold experiment
* *showed dorsal lip's function as an organizer in frog embryos**
- removed a section of dorsal lip from an embryo and transplanted it into belly of another
- a second embryo formed at site of transplant
* dorsal lip formed a notochord which induced formation of a neural plate and neural tube
430
Function of Dorsal Lip in tadpole embryo
acts as an organizer
431
Embryonic induction
| -and how to do with froy embryo
Induce a second embryo to form in another embryo (in frog embryos, by transplanting a dorsal lip into it)
432
Hans Spemann eye experiment
* *indicates a hierarchy of development stages**
- studied successive inductions leading to eye formation
(1) in forebrain, 2 protrusion extending to the ectoderm
(2) when protrusions contact the ectoderm, the ectoderm invaginates and pushes into growing the optic stalk
(3) the optic stalk creates the optic cup
(4) the lens develps from ectoderm that's in contact with edges of optic cup
(5) as lens pulls away remaining ectoderm becomes the cornea
(6) the rest of optic cup develops into the retina
433
cells surrounding the blastocyst; the other cells
trophoblast; other cells are the inner cell mass
434
chorion
layer of cells between trophoblast and fetal blood vessules
435
Placenta
the whole blood exchange apparatus (with human embryos)
436
Changes that the inner cell mass undergoes (in humans)
--Forms a cavity within itself - the amniotic cavity (ectoderm cells line it, and endoderm is below it) ---> now inside the ball have 2 components: (1) amniotic cavity (2) rest of cells important for chorion and placenta
437
Amniotic Cavity
| different to frog embryos
2 Layered (endoderm and ectoderm) sheet that will develop into the fetus (unlike frog embryos, only this portion of the inner cell mass will become the fetus, not the rest of the cells)
438
Primative streak
Human analog to frog's neural plate
| -cells in primative streak migrate to form mesoderm; its formation is the beginning of gastrulation
439
beginning of gastrulation in humans
formation of primative streak
440
Human equivalent of the neural plate
primative streak
441
Chorionic Gonadatropin
Secreted by trophoblastic cells, causes Corpus Luteum to continue to produce estrogen and progestereone
442
What is it that causes the uterus to first contract; then what causes continued contraction
Increasing ratio of estrogen to progesterone (placenta secretes both)lead to beginning of contraction --> causes stress on uterine wall --> signals hypothalamus --> signals posterior pituitary to release oxytocin ---> oxytocin induces more contractions and stimulates production of prostaglandins --> prostaglandins further induce contractions
443
Parturition
the birth process
444
How/why is milk produced (in humans)
Suckling ---> hypothalamus releases PRH (prolactin releasing hormone) --> anterior pituitary releases prolactin ---> epithelial cells in breast (comprise milk glands) are stimulated)
445
How/why is milk ejcted (in humans)
Suckling ---> hypothalamus ---> posterior pituitary releases oxytocin ---> causes contraction of myoepithelial cells in the breast ---> milk gets squezeed out
446
The sequence in which info travels from the CNS to the periphery:
-Cerebral Corte -> Spinal Cord -> efferent neurons -> interneurons -> motor neurons -> muscle tissue
447
Examples of catecholamines
Dopamine, norepinephrine, and epinephrine
448
Effect of chloride ion efflux in action potential generation and activation of actin-myosin cross-lins during muscle contraction
(none)
449
What is neuron depolarization characterized by?
Rapid influx of Na+ into the neuron
450
Effect of Ca2+ on muscle activation
Muscle activation requires release of calcium from the sarcoplasmic reticulum to cause a mechanical response in the muscle
451
spinal cord transection
condition in which the nerves that run inside the vertebral column are damaged (so signals can't pass from brain to muscles)
452
What are frameshift mutations
Adding of deleting a bas
453
Potential effects of frameshift mutations
```
Can cause (in translated protein) different amino acids starting with the one corresponding to the affected triplet all the way to the end of the protein.
-It can also possibly cause the protein to be longer or shorter
```
454
Metastasis
Development of secondary malignant growths at a distance from a primary site of cancer (only occurs once you already have cancer)
455
What is the size of a complete set of human DNA
~3 bilion nucleotides
456
Osmotic gradient of ocean water when swallowed by humans
-Ocean water has a high Na+ and Cl- content, so it has a higher osmolarity if swallowed by humans --> so, will pull water out of the body's cells, leading to dehydration
457
What is a peptide bond?
Amide linkage between the amine group of one amino acid and the carboxylic acid of another group
458
Why is the peptide bond that forms the backbone of proteins especially stable?
- B/c it exhibits RESONANCE STABILIZATION:
| - between the lone pair of the Nitrogen and the double bond in the carbon group
459
What is the 5' GTP cap?
- Where is it formed?
- What is its function?
- Formed on the mRNA of eukaryotes ONLY
- functions to regulate nuclear export, prevent degradation (by exonucleases), promote translation, and promote 5' proximal intron excision
460
What is hybridization?
The process of binding through complementary nucleotides.
461
Polymerization vs. hybridization vs. Elongation
Polymerization = adding nucleotides together to form a single-strand of RNA (or analogous for other molecules)
________
Hybridization = binding through complementary nucleotides
________
Elongation = adding subunits to make a longer strand of macromolecule
462
adsorption
the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface
463
Posphorous and Sulfur in DNA and Proteins
DNA = has P but not S
____
Proteins = has S but not P
464
Transduction
The process by which DNA is transferred from one bacterium to another by a virus
465
transformation
the genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous genetic material from its surrounds through the cellular membrane
466
bacterial conjucation
the transfer of genetic material between bacterial cells by direct cell-to-cell contact or via a bridge-like connection between two cells
467
translation
protein synthesis carried out on the ribosomes of cells
468
DNAse enzymes catalyze _______
the hydrolysis of the phosphodiester linkages of nucleotides in DNA
469
What is the most common capsid shape among viruses?
Icosahedral structure
470
What are some capsid shapes (for viruses)?
- icosohedral (most common) = a shape with 20 faces
- complex = rare, contains 2+ elements of other capsid shapes
- helical = a set of n 1-D molecular helices related by an n-fold axial symmetry; in many rod-shaped and filamentous plant viruses
- prolate = similar to icosahedron, but elongated along the fivefold axis. Comprised of a cylinder with a cap at either end
471
what is a capsid
protein shell of virus (it is NOT an envelope)
472
Genetic Drift
variation in the relative frequency of different genotypes, owing to the chance disappearance of particular genes
473
Gene flow
movement of alleles between populations due to migration
474
Founder effect
Loss of genetic diversity when a new population is founded with a small population
475
2 Reasons why the Y chromosome is more susceptible to mutation
(1) Sperm undergoes many divisions during gametogenesis *more replicative rounds than during oogenesis
(2) females have crossing over events to restore function to damaged X chromosomes
476
Dilation of pupils = sympathetic or parasympathetic nervous system
Sympathetic
477
Aldoseterone
- where released and why
- function
-released from adrenal cortex in response to low blood pressure
____
-Primary function is to increase Na+ reabsorption in the distal tubule - the pump brings in 3 Na+ ions back in for every 2 K+ ions pumped out, so aldosterone also increases the gradient that favors water reabsorption
478
ADH and Aldosterone ---> and their effects on water
Both cause water reabsorption
____
-ADH - increases aquaporin channels in collecting duct
-Aldosterone - increases Na+ reabsorption in the distal tubule and collecting duct, and water follows
479
Telomeres during mitosis
as cell undergoes mitosis, telomeres get progressively shorter - eventually the DNA loses telmoeres entirely and is unable to reproduce - the cell then dies, undergoing apoptosis
480
telomeres
the caps at the end of each strand of DNA that protect our chromosomes;
(are repetitive sequences)
481
autoclaving
the most effective technique for sterilizing used lab material
- an autoclave brings the materials to a temp >120 degrees celsius and a pressure > 2 atm (which is enough to kill almost anything)
482
Mitochondria are found in the _____ of cells
Cytoplasm
483
Mitosis vs. meiosis - which is cyclical
mitosis
484
double crossover event
one in which chromosomal arms of homologous chromosomes cross over in 2 different places along the arm --> resulting in a section in the middle of each chromosome being exchanged
485
of arms (1 or 2) of a chromosome affected by -single and -double crossover events
both only affect one arm of each chromosome
486
Cathode vs. Anode
Cathode = negative electrode --> cations and more basic molecules will migrate towards it
_____
Anode = negative electronde --> anions and more acidic molecules will migrate towards it
_____
**Note: in an electochemical cell, "AnOX Red Cat" - Anode is where oxidation occurs, and cathode is where reduction occurs, so e- are flowing from anode to cathode
487
Which amino acids have basic side chains (at neutral pHs)
(1) Arginine
(2) Lysine
(3) Histidine
488
Troponin - which muscles require it for muscle conraction
skeletal and cardiac (but NOT smooth muscle)
489
Partial double bond character of peptide bonds
delocalization of electron density from the peptide (amide) and nitrogen through the peptide carbonyl carbon and onto the peptide carbonyl oxygen
490
What configuration is the peptide bond nearly always in (and why?)
-the trans configuration, for steric reasons
491
Ionizability of the carbonyl oxygen and amide nitrogen of the peptide linkage at physiological pH
-both are stable and not ionizable at physiological pH
492
Urea - effects on protein
affects higher levels of protein structure but does NOT disrupt peptide bonds
493
3 Main effects of insulin
(1) Body stops making more sugar (decreased gluconeogenesis)
(2) body stores the sugar as glycogen (so increased glycogenesis)
(3) body builds up fatty acids into fats for storing energy (so increased esterification of fatty acids)
494
Oxidation change with additing water
-No next oxidation b/c add 2 protons and 1 oxygen
495
What happens if fatt acid oxidation is stunted
body will rely more on glucose as source of ATP
496
Hardy Weinberg equilibrium
```
allele and genotype frequencies in a population will remain constant from generation to generation in a population, and you can calculate the genotype frequencies by knowing the allele frequencies:
_______
Allele frequences: p + q = 1
______
Genotype frequences: p^2 + 2pq + q^2 = 1
```
497
Pentose phosphate pathway
parallel to glycolysis:
| A process of glucose turnover that produces NADPH
498
What is the primary former of secondary structure
Hydrogen bonds between backbone atoms
499
what holds quaternary structure together
things like hydrophobic interactions and disulfide bridges
500
Nonsense mutation
a substitution in the nucleotide sequence that causes a new, premature stop codon to be inserted in the mature sequene
501
The 3 stop codons in RNA
UGA, UAA, and UAG
502
Fungi vs. bacteria vs. archae ---- which have nuclei
Fungi have nuclei (are eukaryotes) and bacteria and archae do NOT have nuclei
503
Analogous vs. homologous structures
Analogous structures = structures that evolved independently to carry out the same function.
_________
Homologous structures = structures that have a similar evolutionary history (arising from the same source) even if they now have different functions
504
Most eukaryotic viruses are surrounded by what?
An "envelope" = a lipid bilayer
505
pH of endosomes
low (acidic)
506
Positive vs. negative single stranded RNA
Positive = can directly be translated into proteins (negative must first be converted to a positive by RNA polymerase)
507
Where is DNA polymerase primarily found
in the nucleus of eukaryotic cells
508
What are the 3 ways in which bacteria can acquire genes?
(1) transduction (2) transformation (3) conjgation
509
translocation
the exchange of a DNA segment from one chromosome with a DNA segment from another chromosome within a single cell (not considered a gene transfer)
510
ligases
enzymes that catalyze the formation of a bond between two large molecules (such as the formation of phosphodiester bonds between okazaki fragments during DNA replication)
511
pepidases
enzymes that cleave peptide bonds in proteins to formsmaller peptide chains
512
effect of having a "higher binding affinity" on Km and Vmax
Won't affect Vmax, but will lower Km
513
"upstream" means towards which end
5' end
514
Three stages of transcription
(1) initiation = RNA polymerase binds to promoter region of DNA, and then RNA polymerase unwindsDNA at the beginning of the gene
(2) Elongation = RNA polymerase adds nucleotides to 3' end of strand
(3) Termination = transcription stops and mRNA polymerase and the new mRNA transcript are released from DNA
515
What are the only 2 factors which DIRECTLY affect blood pressure
(1) Cardiac output
| (2) Peripheral resistance
516
Effects of Angiotensin II
Increases aldosterone secretion
517
glycogenolysis
vs. glycolysis
vs. gluconeogenesis
vs. glycogenesis
Glycogenolysis = breakdown of glycogen to release glucose
_____
Glycolysis = breakdown of glucose to pyruvate
_____
Gluconeogenesis = synthesis of glucose from non-carbohydrate prcursors (such as proteins)
____
Glycogenesis = synthesis of glycogen from glucose subunits
518
Effect of channel density on action potential initiation
-It doesn't affect action potential initiation
| resting potential is established by ion concentration NOT by channel density
519
Codominance vs. incomplete dominance
Codominance = when both alleles are simultaneously expressed and the phenotype has both traits fully present
_____
incomplete dominance = both alleles are expressed but the phenotype is an average of the two possible phenotypes
520
epigenetic factors
those beyond the DNA sequence that influence gene expression
521
allosteric modulators - how do they function?
by binding to a site other than the active site on a protein, causing a conformational change in the enzyme's 3-D structure (which alters the enzyme's affinity for its substrate)
522
What is the first amino acid in many proteins
- and why?
- and what terminal is it on
Metionine
- the start codon for translation codes for methionin
- on the end of the N-terminus
523
What does the fact that an amino acid has a hydroxyl group tell yo?
the amino acid is polar
524
polar amino acids
- serine
- threonine
- asparagine
- glutamine
- histadine
- tyrosine
525
Hydrophobic amino acids
- alanine
- valine
- leucine
- isoleucine
- proline
- phenylalanine
- trptophane
- cysteine
- methionine
526
Typically for phosphorylation and dephosphorylation to occur, the amino acid'sside chain must contain ____
a hydroxyl group
527
gene knockdown
the artificial manipulation of gene expression
528
Noncoding RNA
RNA molecules that regulate gene expression, but is not translated into a protein
529
Coding RNA
mRNA transcripts that are translated to polypeptides and proteins and typically do NOT directly regulate gene expression
530
alternative splicing
when different introns are spliced out of an mRNA transcript to generate differential gene produces (so, occurs after transcripton, but before translation)
531
Missense mutation
results in a change in the amino acid sequence
532
Initiation mutations
mutations in the initiation codons (in a DNA, which signal for transcription to start), or addition of a new start site
533
Hemoglobin oxygen dissociation curve: what does moving curve right or left mean
moving curve right --> reduced affinity, so need a higher O2 pressure to get the same level of saturation
534
karotype
a picture of isolated and stained chromosomes
535
elevated CO2 in the blood --> effects on pH
decreases pH (increased blood acidity) b/c increases [H+], b/c the enzyme carbonic anhydrase in RBCs catalyzes the interconversion of CO2 and H2O into bicarbonate ions and protons.
536
When are ketone bodies produced
when the liver metabolizes fat
537
pH effects of ketone bodies
increases acidity --- ketones are acidic due to their alpha hydrogen and the resonance stability of the resulting enolate
538
cDNA
complementary DNA, a double stranded DNA synthesized from a single stranded RNA (so reverse transcribing of matrue mRNA, thus it lacks introns)
539
the three main hormones produced by ovaries
(1) estrogen
(2) progesterone
(3) testosterone
540
where is the majority of testosterone produced in females
the ovaries
541
DNA supercoiling
the over- or under-winding of DNA strand; one reason it happens is the strain caused by the unwinding of double stranded DNA
542
chromatin remodeling
a process that occurs as part of DNA organization in the nucleus
543
Gibb's Free energy and protein stability
the more stable a protein is, the lower its Gibbs free energy
544
Peroxisome
a small, membrane enclosed organelle that contains enzymes involved in a variety of metabolic rxns (including several aspects of energy metabolism; some of the enzymes it contains are oxidases)
545
Hypothyroidism and the immune system
-Hypothyroidism affects metabolism but does NOT directly affect immune system
546
Composition of bacterial cell walls vs. fungal cell walls
-Bacterial cell walls = composed of peptidoglycan; fungal cell walls = composed of chitin
547
Effect of noncompetitive inhibitor on Vmax and Km
Reduces Vmax, Km is unaffected
548
Positive control vs. negative control
Positive control = a trial in which an effect is expected to occur
__
Negative control = a trial in which no effect is expected
549
Southern Blot vs. Northern Blot vs. Western Blot
```
Southern Blot = measures DNA
______
Northern Blot = measures RNA
______
Western Blot = measures protein (so is a direct measurment of protein expression)
```
550
Antidiuretic Hormone
> increases the # of aquaporins transport enzymes in the collecting tubule of the nephron (aquaporins reabsorb water). So, more water is reabsorbed.
551
Catalysts - what they affect and what they do not affect
- Affect: rxn velocity and activation energy
| - Do not affect: deltaG, euilibrium constant
552
lacteals
structures in the intestines associated with absorbing fat into the lymphatic system
553
epiglottis
a flap of cartilage at the root of the tongue, which is depressed during swallowing to cover the opening of the windpipe
554
What are the viable autosomal Trisomies
Triosmy 21, 18, and 13
555
what are the viable autosomal Monosomies
(there are NONE)
556
Acrocentric Chromosome
a chromosome in which the centromere is located quite near one end of the chromosome (humans have 4)
557
how many chromosomes do humans have
46 (23 pairs)
558
baroreceptors
a subclass of mechanoreceptors located in the walls of blood vessels as well as the atrial ventricular walls of the right side of the heart (detect stretch - signaling changes in luminal pressure)
559
Arachidonic Acid
- what it is
- what it is a precursor for
an important precursor for the biosynthesis of the eicosanoid signaling molecues: prostaglandins, thromboxanes, and leukotrienes
560
Catecholamines
A class of molecules derived from tyrosine
561
Structure of formaldehyde
H2C = O
562
Structure of Methanol
CH3OH
563
What type of protein are most transmembrane proteins
glycoproteins
564
Phospholipids
| -what and where they are
located on the cell surface (don't typically extend through the bilayer)
--are a structural component
565
Glycolypids
| -what they are and where they are
Located on the cell surface (don't usually extend through entire bilayer)
-act to provide energy and also searve as markers for cellular recognition
566
what is the largest amino acid and how large is it
tryptophan, 204 Da
567
Types of synapses in parasympathetic nervous system (and why)
Primarily chemical synapses, because the response is not as fast as the fight-or-flight
568
IF the structure of an inhibitor is different than the substrate, it is not likely a _____ inhibitor (and why)
NOT a competitive inhibitor - because if the structure is different, it probably isn't binding to the same site
569
siRNA
binds to other RNA strands and prevents them from being translated
570
Results of Meiosis I
2 haploid cells, each with 23 chromosomes of 2 sister chromatids per chromosome
571
result of meiosis vs. mitosis
Mitosis --> results in diploid daughter cells
--
Meiosis --> results in haploid cells
572
X- and Y-intercept of Lineweaver-Burk Plot
```
X-intercept = -1/Km. So if Km increases (due to a competitive inhibitor), the X-intercept will become closer to zero.
Y-intercept = 1/Vmax. So if Vmax decreases (due to a non-competitive inhibitor), 1/Vmax will increase, so the intercept will become further from zero
```
573
Effect of competitive inhibitor on Lineweaver Burk Plot
X-intercept is closer to 0, Y-intercept is the same
574
Effect of noncompetitive inhibitor on Lineweaver Burk Plot
X-intercept is same, Y-intercept is further from 0
575
Nucleoside vs. Nucleotide
Both are a nitrogenos base + five carbon sugar
____
Nucleotide also has 1-3 phosphate groups
576
What are the most common nucleosides and nucleotides
Nucleosides = cytidine, uridine, adenosine, guanosine, thymidine, inosine, etc.
_____
Nucleotides = IMP, GTP, etc.
577
what is hypoxanthine
a nitrogenous base
578
What germ layer is the nervous system derived from
ectoderm
579
mesoderm gives rise to what structures
bone, cardiac muscle, skeletal muscle, smooth muscle, and tissues involved in the exretory and reporductive systems
580
what are ribosomes made of
RNA
581
What are the 3 types of hormones?
(1) peptide (insulin, etc.)
(2) amine (epinephrine, adrenaline, etc.)
(3) steroids (sex hormones, etc.)
582
What are the 2 ways a hormone acts on a target cell
(1) by binding to a membrane receptor - which causes a conformational change of the complex, allowing for the synthesis of a secondary messenger that transmits the info from the hormone
(2) by passing through the membrane and binding with a specific target protein in the cytoplasm
583
epinephrine = ____ soluble
water
584
several examples of nucleotides
GTP, GDP, ATP, and ADP
585
What is the casacade/action process for epinephrine
(1) Stress causes nervous system to signal adrenal medulla to release epinephrine ---->
(2) Epinephrine binds to Beta-adrenergic receptor on hepatic cell membrane --->
(3) GDP is initially bound to the G-protein, but after epinephrine binds, the complex interacts with the G-protein and causes the exchange of GDP for GTP --->
(4) This complex activates adenlate cyclase enzyme, which will catalyze the synthesis of [cAMP] from ATP (thus increasing [cAMP], a secondary messenger in cells)
586
protein kinase enzyme
transfers the end phosphate (the gamma phosphate) of ATP to a specific amino acid residue of a substrate protein
587
How is a G-Protein inactivated
It hydrolyzes the bound GTP to GDP and Pi, inactivating the G-Protein
588
Protein Kinase A (PKA)
cAMP binds to it and stimulates it to phosphorylate the glycogen phosphorylase enzyme, thus activating the enzyme, which will catalyze the conversion of glycogen to glucose
589
cholera
intestinal disorder caued by a bacterium. Major symptoms = diarrhea. Toxin Binds to active state of G protein and prevents GTP hydrolysis to GDP and Pi (so adenylate cyclase is continually active and massive amounts of cAMP are synthesized, causing intestinal cells to secrete digestive fluids)
590
gastrin
water soluble peptide hormone --> stimulates secretion of HCl and pepsinogen (from the stomach) in response to stimulation from the vagus nerve and partially digested protein
591
Action of Gastrin
(1) Binds to receptr
(2) G Protein is activated
(3) G Protein interacts with membrane enzyme phospholipase C (PLC) to form IP3 and DAG from PIP2
(3) IP3 (the secondary messenger) interacts with the endoplasmic reiculum to stimulate Ca2+ rlelease. DAG diffuses through the plasma membrane and stimulates protein kinase C (with help of Ca2+) to phosphorylate a protein the causes HCl secretion into the lumen of the stomach
592
How is a G protein activated
by replacing GDP for GTP
593
insulin is ____ soluble
water
594
Action of insulin
(1) Insulin binds to its receptor
(2) cytoplasmic portion of receptor is converted to a tyrosine kinase
(3) tyrosine kinase autophosphorylates tyrosine (further enhancing tyrosine kinase's activity. the receptor can also internalize and act as a secondary messenger)
(4) this increased tyrosine kinase activity leads to internalization of glucose
595
steroid and thyroid hormones
lipid soluble hormones which can pass through the cell's plasma membrane and interact with a receptor either on the cytosol or in the nucleus
596
thyroid hormone: -where it binds, -effects
- binds to receptors in the nucleus, which activates transcription;
- effects: can help regulate growth and differentiation, and can stimulate the breakdown of proteins, fats, and glucose
597
precursor for ALL steroid hormones
Cholesterol
598
2 important classes of steroid hormones
(1) Androgens and (2) Estrogens
599
Estrogen is ____ soluble. Where does it bind.
Lipid soluble, binds to a cytoplasm receptor and complex can then enter nucleus and influence the transcription of mRNA for certain products.
600
the only fuel utilized by the brain (except when fasting, which uses ____)
Glucose, except for fasting - when the brain uses ketone bodies
601
2 hormones released by pancreas (And which cells secrete them)
(1) Insulin (by Beta cells) and (2) Glucagon (by alpha cells)
602
When is insulin secreted. By what? and what does it do
-When [glucose] is high. Secreted by beta cells of pancreas. Promotes reuptake of glucose. Binds to receptors on liver, fat, and muscle cells
603
When is glucagon secreted. By what? and what does it do
- when glucose is low. Secreted by alpha cells of pancreas. Binds to liver and fat cell receptors.
- Stimulates liver cells to degrade glycogen to glucose
- Also stimulates fat cells to release fatty acids (which can be metabolized and used in Krebs cycle for energy)
604
2 Hormones released by posterior pituitary
(1) Oxytocin and (2) Antidiuretic Hormone
605
Hormones released by the posterior pituitary are synthesized in the ____ \
hypothalamus and then travel to posterior pituitary for release
606
oxytocin: where it comes from and what it does
- comes from posterior pituitary (synthesized in hypothalamus
- stimulates female uterine contractions
607
Antidiuretic Hormone: Where it comes from
Released by posterior pituitary (and synthesized in hypothalamus)
608
ADH: what it does
Stimulates water reabsorption in the kidneys and helps increase blood volume (and pressure)
609
How ADH works
Reaches kidneys and stimulates [Na+] reabsorption and also water reabsorption. Hypothalamus detects changes in Na+ and water, and synthesizes ADH accordingly
610
Hormones secreted by the anterior pituitary
"(1) Thyroid Stimulating hormone (TSH);
(2) Adrenocorticotropic Hormone (ACTH);
(3) Follicle stimulating hormone (FSH);
(4) Luteinizing Hormone (LH);
(5) Growth Hormone (GH);
(6) Prolactin"
611
Virus vs. bacteria
Virus is much smaller
612
Composition of Viruses
Contain a nucleic acid core (RNA or DNA) surrounded by a protein coat
613
Blood cell types
"(1) Erythrocytes = Red blood cells;
| (2) Leukocytes = White blood cells"
614
Where are erythrocytes (RBCs) produced
In the marrow of the sternun, ribs and vertebrae
615
Where are leukocytes (WBCs) produced
Partially in lymph tissue and partially in bone marrow
616
How many types of WBCs are they? What are the ones to remember
6 Types; Remember: (1) Monocytes, (2) Neutrophils, (3) Lymphocytes
617
Phagocytes
Cells that ingest harmful materials
618
Which WBCs are considered phagocytes (and which aren't)
Are: Monocytes and neutrophils; Aren't: lymphocytes
619
What happens to monocytes once they enter tissue
Are transformed to macrophages
620
What are the primary phagocytes of the body
Macrophages and neutrophils
621
How do Macrophages and Netrophils attack and destroy foreign bacteria and viruses
Through phagocytosis: engluf invader by endocytoses, and then phagocyte lysosomal enzymes or H2O2 is released, degrading foreign objects
622
Mast Cells
Derived from leukocytes, release histamine when stimulated which acts on endothelial cells and causes increased permeability to cells like neutrophils, so neutrophils can easily access surrounding tissue to defend against foreign invaders
623
2 Types of lymphocytes
(1) T cells and (2) B Cells
624
Where are T cells produced
Thymus Gland
625
3 Types of T Cells
(1) Cytotoxic T Cells (2) Helper T Cells (3) Suppressor T Cells
626
T Cells are responsible for what type of immunity
Cell-Mediated immunity = responsible for the destruction of foreign microorganisms and other harmful agents
627
Where are B Cells produced
Bone Marrow
628
B Cells are responsible for what type of immunity
Humoral Mediated Immunity = differentiate into plasma cells which release antibodies
629
Antibodies = what type of macromoleucle
Protein
630
Steps in Cell Mediated Immunity
"(1) Macrohpage engulfs & phagocytoses foreign particle
(2) Antigen fragments on foreign particle are released into cytosol and transported to macrophage membrane - where bind to MHC-Class 1 protein
(3) Receptors on Cytotoxic T cells recognize antigen-MHC 1 complex & bind to it
(4) Binding causes macrohphage to release interleukin-1 growth factor (and cytotoxic T cell releases Interleukin-2)
(5) Interleukins 1,2, and other interleukins released by Helper T Cells stimulate synthesis of more Cytotoxic T Cells
(6) Cytotoxic T Cells proliferate and bind to the cells bearing the antigen, causing them to lyse"
631
Humoral Mediated Immunity: steps
"(1) Antigen binds to antibody on a B Cell
(2) B Cell engulfs antigen-antibody complex
(3) B Cell transports portion of antigen to Class II MHC on surface
(4) Helper T Cells bind antigen-Class II MHC Complex
(5) Binding stimulates release of interleukins by T cells
(6) Interleukins stimulate B cells to proliferate and form plasma cells
(7) plasma cells produce a vast amount of antibodies specific to the antigen
(8) Antibodies circulate and bind to antigens, ""tagging"" for phagocytes
(9) Phagocytes engulf & destroy the antigen-antibody complex"
632
Structure of immunoglobins
"Y-shaped with 4 subunits connected by disuflide bridges;
| 2 light & 2 heavy chains, each with a variable and constant domain"
633
3 Regions of Variable domain on immunoglobulins
"(1) Variable (V) = can differ in amino acid sequence; contains the antigen-binding site
(2) Diversity (D) = only on heavy chain, and (3) Joining (J)"
634
Classes of immunoglobulins, and how they differ
"IgA, IgB, IgE, IgG, and IgM
| Differ in heavy chain composition"
635
The primary ways antibodies identify foreign invaders
"(1) Directly blocking them from gaining access to cells (by binding)
(2) Binds and causes a complement protein to recognize, which triggers immune response
(3) Bind and coat the cell surface - so phagocytes can come"
636
Structure of T Cell recepotors
Composed of 2 polypeptide chains, each with a constant and variable region. One chain's variable domain has V and J regions, the other's has V,D,and J regions
637
Function of Cytotoxic T Cells
Recognize MHC-1 - antigen complex, bind to it, and cause lysis the host cell that contains the virus
638
Function of immature Helper T Cells
Recognize macrohpages that present Class II-MHC - antigen complex and bind; causing release of interleukin 1 and 2 - stimulating the immature cells to proliferate into mature Helper T Cells, which also secrete interleukin-2, which activates Cytotoxic Cells, B cells, and more Helper T Cells
639
Suppression of LH vs. of FSH in women
Suppress FSH = prevent follicular growth; suppress LH = prevent ovulation
640
Leydig vs. Sertoli cells: what they do, and what they are stimulated by
Leydig = synthesize testosterone (stimulated by LH); Sertoli = promote spermatogenesis (stimulated by FSH)
641
What type of cells secrete histamine
mast cells AND basophils
642
B cells and T cells: where each are produced, and where each mature
Both are produced in bone marrow. B cells mature in the Bone marrow, and T cell mature in the Thymus
643
skin cells of the epidermis are called _____
keratinocytes
644
Leukocytes vs. Lymphocytes
Leukocytes WBCs. There are 5 types of WBCs (neutrophils, basophils, eosinophils, monoytes, and lymphocytes ) -- thus lymphocytes are a type of leukocyte (lymphocytes are T cells or B cells)
645
integument
tough outer layer of plants and animals (aka OUR SKIN)
646
What is the M line
the center of the H zone (the center of the sarcomere)
647
nonsense vs. missense mutations
missense = substituiton; nonsense = adds new startcodon
648
how many genes are on the Y chromosome
very few
649
All 20 standard amino acids are _____ except ___ which is _____
All are alpha-amino acids; except Proline, which is an alpha-imino acid
650
What type of amino acids are found in proteins
only the L-amino acids
651
How is histamine formed?
From the decarboxylation of histidine
652
What is SAM and how is it formed?
S-Adenosylmethionine; active form of methionine. Can methylate protein or nucleiuc acids
653
Structures of polypeptide chains - 2 most common
"Alpha-helices: stabilized by Hydrogen bonding between CO and NH groups (within the same chain); (roughly 3.6 amino acids per turn). Side chains extend outward.
_____
Beta-pleated sheets: stabilized by Hydrogen bonding between CO and NH groups (Between different chains); polypeptide chains can be parallel or antiparallel; polypeptide can make a beta-turn and fold back to run in opposite direction (Hydrogen bond at turn is 3 residues away)"
654
Primary vs. Secondary vs. tertiary vs. quaternary structure
Primary = amino acid sequence and location of disulfide bonds; Secondary = spatial arrangement of amino acids that are close together; tertiary = spatial arrangement of amino acids that are far from one another; quaternary = how various subunits associate with one another
655
leucine zipper
forms if 2 alpha-helices, each with 4+ leucine residues and located on separate proteins, come together through interdigetation of the leucine residues
656
Carbohydrate
An aldehyde or ketone group and 2+ alcohol functional groups
657
Ketoses vs. Aldoses
```
"Ketoses = monosaccharide (carbohydrate) with a ketone group; vs.
Aldoses = monosacchardie (carbohydrate) with an aldose group"
```
658
Most naturally occuring monosaccharides are ______ isomers
D isomer
659
D vs. L isomer of monosaccharides
L = hydroxyl group is to the left of the reference carbon (the chiral carbon furthest from the cabonyl carbon) vs. D isomer = hydroxyl group is to the right of the reference carbon
660
pyranoses and furanoses
pyranoses = cyclic sugar with a 6-membered ring; vs. furanoses = cyclic sugar with a 5-membered ring
661
alpha pyranose/furanose vs. beta
alpha = the -OH group at the anomeric carbon is on opposite side of ring as the -CH2OH; beta = the -OH group at the anomeric carbon is on the same side as the CH2OH
662
Anomeric Carbon
Alpha and Beta carbohydrates are anomers b/c they differ only in configuration - around C-1, which is thus the anomeric carbon
663
How are furanoses formed?
Oxygen atom from C-5 alcohol group reacts with ketone group (C-2)
664
How are pyranoses formed?
Oxygen from C-5 hydoxyl group reacts with carbonyl aton (C-1) to form 2 different diastereomers
665
Hemiacetal
Alcohol + aldehyde product
666
Hemiketal
Alcohol + ketone
667
Reducing Sugars
Carbohydrates that are capable of reducing the Ag+ ion to silver metal in Tollen's reagent and can reduce the Cu2+ ion in Benedict's reagent to give brick-red precipitate ---> b/c the sugar contains a free ketone or aldehyde group
668
What are oligosaccharides?
Relatively short chains of monosaccharides linked to one another by a glycosidic bond
669
What type of bond links monosaccharides together?
Glycosidic bonds
670
Sucrose - reducing or non-reducing?
Non-reducing
671
Show to name sugars?
"(1) Start with an ""O"" if an O-glycosidic bond (linked by an Oxygen)
(2) Name the first sugar - alpha or beta; L or D (D if natural); then name
(3) List the carbons participating in the bond (ex: 1->4)
(4) End with ""-ide"" if it is a reducing sugar"
672
lactose
dissacharide found only in milk - composed of galactose and glucose; reducing
673
Starch
dissarcharide - compsed of glucose and fructose); non-reducing
674
homopolysaccharides vs. heteropolysaccharides
homo = consist of just one type of monosaccharide; (hetero = consist of different types)
675
how is starch digested?
First by Alpha-Amylase enzyme in the mouth, then further by pancreatic-alpha-amylase
676
Lipids
Molecules that can readily dissolve in nonpolar solvents but are relatively insoluble in water
677
fatty acid structure
carboxylic acid with a hydrocarbon side chain
678
Triacylglycerol structure
Glycerol backbone + 3 fatty acids
679
Triacylglycerol melting point & saturation level
More saturated = better packing, so higher melting points
680
Structure of glycerophospholipid
2 Fatty acids esterfied to glycerol; contain a phosphate group; ampiphilic - nonpolar tails (fatty acid) and polar head (phosphate)
681
predominant lipid component of all bio membranes
glycerophospholipid (aka phosphoglyceride), a type of phospholipid
682
sphingolipids
lipids not based on a glycerol backbone, instead, are derivatives of amino alchohols
683
sphingosine
common sphingolipid derivative
684
ceramide
sphingolipid with fatty acid attached at C-2 via an amide bond
685
sphingomyelin
type of sphingosine (if posphocholine or phosphoethanolamine is attached to C-1 of ceramide); common in myelin sheaths
686
cerebroside
Sphingolipid with single monosaccharide attached to the C-1 of ceramide
687
what is one believed purpose of extended oligosaccharide residues on a ganglioside?
Molecule Recognition
688
where is cholesterol synthesized? What does it typically exist as?
In cytosol; typically exists as cholesterol ester
689
Plasma membranes - major lipid component
Cholesterol
690
Structure of cholesterol
Fairly rigid set of 4 fused nonpolar rings and a polar hydroxyl group (so slightly ampiphilic)
691
Where are steroid hormones synthesized?
In the mitochondria
692
How are steroid hormones synthesized
"(1) Begins with hydrolysis of cholesterol esters in cytosol
(2) Then, transport cholesterol into mitochondrian
(3) ACTH stimulates conversion of cholesterol to pregnelone
(4) pregnelone is then converted to progesterone (which is finally converted to cortisol, aldosterone, and testosterone - which is converted to estradiol)"
693
what does a nucleotide consist of
"(1) a Nitrogenous base
(2) a pentose sugar
(3) phosphoric acid"
694
Nucleotide vs. nucleoside
Nucleoside = nitrogenous base + pentose sugar; Nucleotide = nucleoside + 1 to 3 phosphate groups
695
Pentose sugars in DNA and RNA
in DNA: 2'-deoxy-D-ribose; in RNA: D-ribose
696
Structure of DNA and RNA
Backbone of alternating pentose sugars and phosphate groups -- nitrogenous bases are attached to the sugars
697
What links together nucleotides in DNA and RNA
phosphodiester linkages
698
Role of phosphoric acid in DNA and RNA:
"(1) Excellent buffering capacity -- b/c has 3 pKa values
(2) makes the backbone polar -- since the Hydrogen on the hydroxyl grop has a pKa of around 3, so phosphate in DNA and RNA has a negative charge."
699
DNA Structure: per single strand
Nitrogenous bases are connected to the sugar by a N-glycosidic linkage & the nucleotide units are connected by phosphodiester bonds --> both are formed by a dehydration rxn (so can be hydrolyzed
700
How are DNA strands connected
"through interactions with nitrogenous bases:
- base pairing: A and T can be paired through 2 hydrogen bonds & G and C can be paired by 3 Hydrogen bonds ---> the two strands wrap around eachother
- At the 5' end, have an unreacted Phosphate group and at the 3' end have an unreacted hydroxyl group"
701
Types of RNA
"(1) mRNA (messenger RNA) = RNA polymers that allow for the synthesis of proteins
(2) tRNA (transfer RNA) = bring amino acids to site of protein synthesis
(3) rRNA (ribosomal RNA) = help define the ribosome"
702
chromatin
complex of linear doubl stranded DNA and protein (histones) - found in the nondividing (interphase) cell; as cell prepares for division - will become highly organized into chromsomes
703
somatic cell
cells which aren't gametes; are diploid - have 23 pairs of chromosomes in humans
704
karotype
the characteristic size and shape of the chromosomes in metaphase
705
Classification of chromsomes based on centromere location
metacentric = centromere in the middle; acrocentric = very small p arm (centromere near end); submetacentric: p arm just a little smaller then q arm; telocentric = no p arm - centromere is on end
706
p and q arem of chromosomes
p = short end, q = long end
707
histones
most abundent type of protein associated with DNA; consist of a high percentage of Lys & Arg residues --> so can form electrostatic relationships with negatively charged DNA
708
linked & histones
linker = the region separating histones
709
nucleosome
defined by the association of histones with DNA; each nucleosome repeats ~every 200 pairs
710
Nonhistones
any protein that associates with DNA that isn't a histone. Is NOT basic - instead, is acidic (with a negative charge). Ex: RNA polymerase
711
Phases of interphase
(1) G1 phase (2) S phase (3) G2 phase
712
What happens in G1 phase of interpase
Growth phase; RNA and proteins are actively being synthesized
713
What happens during S phase of interphase?
All 46 strands of chromatin are duplicated --> get 92 sister chromatids (but only 46 chromosomes still); daughter centrioles are synthesized
714
What happens during G2 phase of interphase
Chromatin begins to condense and become tightly coiled; more growth
715
Phases of mitosis
(1) Prophase (2) Metaphase (3) Anaphase (4) Telophase
716
What happens during prophase of mitosis?
Centriole pairs move apart; microtubules radiate from each centriole pair - forming an aster; chromosome condensation completes
717
What happens during metaphase of mitosis?
Chromosomes align along equator of the cell - a region called the metaphase plate; nuclear envelope now completeley gone
718
What happens during anaphase of mitosis?
centromeres of each chromosome divide & the 2 sister chromatids move towards opposite ends; cytokinesis begins
719
What happens during telephase
undoing prophase - each chromosome begins to unwind, microtubules disappear, nuclear membrane begins to form; cytokinesis continues
720
cytokinesis
cleavage of 1 cell into 2 daughter cells; usually begins late anaphase; when complete - signals end of mitosis
721
Interphase in meiosis
Preceeds both Meiosis I and Meiosis II - the Interphase before Meiosis 2, though, doesn't have S phase (b/c don't get replication)
722
Steps to Prophase I of meiosis
(1) Leptotene (2) zygotene (3) pachytene (4) diplotene (5) diakinesis
723
What happens in step 1: leptotene of Prophase I?
Replicated chromosomes have already started to condense - and now become visible (have 23 from mother and 23 from father)
724
What happens in step 2: zygotene of Prophase I?
Have synapsis: homologous chromosomes pair --> get tetrads; synaptonemal protein appears between pairing chromosomes and facilitates their union
725
What happens in step 3: pachytene of Prophase I?
Genetic recombination occurs through crossing over
726
What happens in step 4: diplotene of Prophase I?
Crossing over happens at chiasmata
727
Chiasmata
the site on chromosomes where crossing over occurs
728
tetrads
pairing of 2 homologous chromosomes - in preparation for crossing over
729
What happens in step 5: diakensis of Prophase I?
Chiasmata reaches ends of chromatids --- homologous chromosomes begin to separate and appear joined at ends; nuclear envelope breaks down
730
What happens in Metaphase I?
Homologous chromosomes align on the metaphase plate; microtubules from spindle apparatus attach to centromeres
731
centromeres vs. centrosomes vs. centrioles
Centromeres = point on chromosomes that is attached to the mitotic spindle (during mitosis/meiosis); centrioles = organelle involved in mitotic spindle formation - have a pair of them within the centrosome
732
What happens in anaphase I?
Microtubules pull apart the homologous chromosomes (But centromeres DON'T DIVIDE); pair of sister chromatids - known as a dyad - migrate to one end; cytokinesis begins
733
What happens during telephase I?
Dyads complete movement; cytokinesis more pronounced
734
Asexual reproduction happens in what type of organism (haploid or diploid)
Can happen in either haploid or diploids
735
3 Major components of eukaryotic biological membranes
(1) Glycerophospholipids; (2) Sphingolipids; (3) Cholesterol
736
Most abundant glycerophospholipid in the cell membrane?
phosphtidylcholine & phosphatidylethanolamine
737
Factors influencing membrane fluidity:
(1) Short fatty acid side chains = increased fluidity (2) more cis unsaturation = increased fluidity (3) Cholesterol: acts as a fluid buffer - at high temps, decreases fluidity, and at low temps, increases fluidity (4) increasing temp = increased fluidity
738
What are glycoproteins and glycolipids?
Carbohydrates on either the proteins embedded in the lipid bilayer of membranes or directly in the lipid bilayer of membranes; play important roles in cell recognition
739
The endoplasmic reticulum is single or double membraned
Double
740
functions of smooth endoplasmic reticulum
(1) Synthesizes lipids (for cell membranes, and secretory lipids) (2) metabolizes carbohydrates (3) Aids in detoxification of drugs and toxins
741
Functions of Rough Endoplasmic Reticulum
(1) Site of protein synthesis (for proteins secreted into extracellular environment, integral proteins, and proteins that remain in the ER, golgi, and lysosomes) (2) some post translational protein modification (such as forming disulfide bridges)
742
What are the lipid components of cell membranes?
(1) Phospholipids (and phosphatids) (2) Steroids (3) Waxes
743
What is the fluid mosaic model?
The model of a cell membrane: says membranes are made up of distinct components, which can move around
744
What are the factors affecting membrane fluidity
(1) Cholesterol = like a buffer: at high temps, it decreases fluidity; at low temps, it increases fluidity (2) More cis unsaturation (double bonds) = increased fluidity (3) Increased temp = increased fluidity
745
Simple vs. facilitated diffusion
Both are passive transport diffusion (down a gradient); simple = solutes move directly through lipid bilayers; facilitated = depend on interaction with membrane protein (a protein channel
746
Permeases
Protein channels
747
Types of Facilitated diffusion
(1) Uniport (1 molecule, 1 direction) (2) Symport (2 molecules, same direction) (3) Antiport (2 molecules, different directions)
748
What is a colligative property? Is osmosis a colligative property?
Depends on # of solute molecules, but not type of solute
749
Sodium/Potassium Pump is called what (more formally) and is what type of pump?
Na+ K+ ATPase ---> active transport
750
Group Translocation
Type of used for sugar transport across membrane - sugar residue is phosphorylated as being transported through plasma membrane
751
Bulk Transport
Exocytosis or endocytosis
752
Types of endocytosis
Phagocytosis (if vesicle contains particulate matter); pinocytosis (if vesicle contains liquid portion of exctracellular matrix)
753
What are the defining characteristics of Eukarytoic Cells
(1) Membrane bound nucleus (2) Presence of Organelles (3) Mitotic Division
754
Nucleolus
Center of nucleus - compact and dense; site of ribosomal assembly (where rRNA is assembled with proteins to make a fully formed ribosome, which will be trafficked out into cytoplasm via nuclear pore)
755
Nuclear Pore
Transports across nuclear membranes (mRNA out, Protein in, etc.)
756
Nuclear Envelope
Combination of inner + outer membrane with the nuclear pores
757
3 Defining characteristics/functions of mitochondria
(1) Site of ATP production (2) Inner + outer membranes (3) Self-replicates
758
Mitochondria - outer membrane structure and permeability
Made of a lipid bilayer & permeable to small molecules
759
Mitochondria - inner membrane structure and permeability
Made of a lipid bilayer - folded into cristae (increased surface aea = more area for cellular replication) & impermeable; also, studed with Electron Transport Chain Enzymes
760
Mitochondrial Matrix
center (inside of inner membrane) of mitochondria
761
Steps to Cellular respiration
(1) Glycolysis (2) Pyruvate Dehydrogenous Complex (PDC) turns pyruvate into acetyl-CoA (3) Krebs Cycle turns Acetyl-CoA into NADH and FADH2 (e- carriers) (3) ETC - makes ATP using NADH and FADH2
762
Where in cell does glycolysis occur
In cytoplasm (only step of cellular respiration that doesn't occur in mitochondria)
763
Where is the Pyruvate Dehydrogenase Enzyme
In the Mitochondrial Matrix
764
Where does the Krebs cycle take place
Mitochondrial Matrix
765
Where does the ETC take place?
In inner mitochondrial matrix
766
What is the lysosome
Membrane bound vesicles containing acid hydrolase enzymes; digests molecules and substances - and releases building blocks into cytoplasm
767
Which proteins are synthesized in the cytoplasm vs. the Rough ER
Cytoplasm - proteins that will end up in: nucleus, mitochondria, peroxisomes, cytoplasm; Rough ER, proteins - secreted into extracellular environment, integral membrane proteins, or proteins for lysosomes, ER, golgi
768
What is the secretory pathway
(1) All proteins being translation in the cytoplasm (2) Proteins marked for secretory pathway have a signal sequence - detected early on, pushes protein to rough ER, where translation is finished (3) Protein butts off in vesicle from Rough ER (4) Vesicle merges with Golgi apparatus, protein is released into Golgi where it is modified (5) Vesicle containing protein breaks off from Gogli (6) Veiscle with protein goes to membrane (where it is secreted or becomes part of membrane) or lysosome
769
3 Functions of Golgi Apparatus
(1) Modifies Proteins made in Rough ER (2) Sorts and sends proteins to proper destination (3) Synthesizes certain molecules that needs to be sorted
770
structure of golgi apparatus
Groups of sacks stacked together (cis stack = closest to rough ER; medial stack = in middle; trans stack = further from ER)
771
Peroxisomes
Organelles that collect peroxides & break them down (has a catalase enzyme) into water and oxygen
772
Functions of cytoskeleton
(1) Structural Support (2) Movement (3) Transport
773
Microfilaments - composition & functions
Composition = actin polymers twisted around; Functions = cleavage (such as in cytokinesis) and cellular contractions
774
Intermediate filaments - composition & function
Composition = many different proteins form polymers & wrap around; Function = structural support (resist mechanical stress)
775
Microtubules - composition
alpha-tubulin + beta-tubulin dimer -- forming a sheet --- forming a tube; one side is anchored to a microtubule organizing center and the other is dynamic (can grow)
776
types of MTOC (Microtubule Organizing Systems
(1) Centrosome (2 centrioles which are made up of microtubules & form mitotic spindle - in metaphase) (2) Basal Bodies (Attach to flagella or cilia, enabling them to move)
777
9+2 Arrangement
Structure of cillia and flagella - have 9 pairs + 1 pair in center of microtubules; nexin (protein) in between pairs and dynein (protein) coming out of microtubules - which breaks down ATP & helps mitochondria move past eachother, moving cillia/flagella
778
"Railroad Track" in neurons
formed by microtubules - with kinesis and dynein - help shuttle compounds/vesicles/etc. from one end of neuron to other (can go both ways)
779
Function: Microfilaments vs. intermediate filaments vs. microtubules
Microfilaments = cleavage & contractility; Intermediate filaments = structural support; Microtubules = (1) Mitotic Spindles (2) Cillia/Flagella mvmt (3) Railroad track in neurons
780
composition of flagella: eukaryotes vs. prokaryotes
eukaryotes: made of microtubules; prokaryotes: made of flagellin protein
781
composition of cilia:
(only found in eukaryotes) made of microtubules
782
Cell division: eukaryotes vs. prokaryotes
Eukaryotes: mitosis; prokaryotes: binary fission
783
Cell Theory
(1) Cell is the basic structure of life (2) All living things are made of cells (3) All cells come from previous cells
784
Prokaryotic Domains
(1) Archae (2) Bacteria
785
Major classifications of bacteria
(1) Bacilli (rod-shaped) (2) spirilli (spiral-shaped) (3) Cocci (spherical-shaped)
786
Defining characteristics of prokaryotes
(1) Lack of nuclear membrane (2) Lack of mitotic apparatus (3) Lack of typical eukaryotic organelles (4) Presence of cell wall (in bacteria)
787
Size of ribosome in eukaryotes & prokaryotes
Eukaryotes: 80S (made up of 60S + 40S); Prokaryotes: 70S (50S + 30S)
788
Bacteria: aerobic or anaerobic
There are both anaerobic and aerobic bacteria
789
Bacteria growth
exponential (until run out of food, etc.)
790
Nucleoid
region containing the circular double-stranded DNA chromosome in bacteria
791
Plasmid
extragenomic DNA that some bacteria have (could allow drug resistance)
792
chemotaxis
Why bacteria move - by attraction towards or away from certain chemicals
793
How and why do bacteria move
How: flagella; why: chemotaxis
794
Gram positive vs. gram negative bacteria
Gram positive (stain blue) - have one thick peptidoglycan cell wall just outside of plasma membrane; Gram Negative (stain pink) - have one thin peptidoglycan layer (in between membranes) AND an outer cell membrane made of lipopolysaccharides and porins
795
transformation & conjugation
transformation = uptake of genetic material (by bacteria) from the surrounding medium; conjugation = transfer of genetic info by cell-cell contact
796
Transduction
Transfer of bacterial genes by viruses
797
Transposons
(in eukaryotes and prokaryotes) DNA sequence that can change its position within a genome (can alter code); in bacteria - antibiotic resistance plasmids can be conjugated via transposons onto other bacteria
798
aster
describes the star shaped structure around the Centrioles during mitosis; Astral microtubules = the microtubules branching off from it (don't connect to kinetochores)
799
Virus structure
Nucleic Acid + surrounded by protein coat
800
Virus Capsids vs. Nucleocapsid
If no nucleic acid in the shell = capsid; if has nculeic acid in the shell = nucleocapsid
801
Enveloped vs. Non-enveloped viruses
Enveloped = enveloped by lipid membraned (derived from host cells) attached to nucleocapsid by matrix proteins
802
Genome of viruses
Can be RNA or DNA; single stranded or dobule stranded
803
Positive and negative strands in Viruses
mRNA template = + strand. If DNA/RNA has identical sequence, then it is also +, if not, then it is -.
804
Organelles and nucleus in virus
Don't have either
805
Bacteriophage structure
Head (contains nucleic acid); tail; tail fibers; spikes
806
All 20 standard amino acids are _____ except ___ which is _____
All are alpha-amino acids; except Proline, which is an alpha-imino acid
807
What type of amino acids are found in proteins
only the L-amino acids
808
How is histamine formed?
From the decarboxylation of histidine
809
What is SAM and how is it formed?
S-Adenosylmethionine; active form of methionine. Can methylate protein or nucleiuc acids
810
Structures of polypeptide chains - 2 most common
"Alpha-helices: stabilized by Hydrogen bonding between CO and NH groups (within the same chain); (roughly 3.6 amino acids per turn). Side chains extend outward.
_____
Beta-pleated sheets: stabilized by Hydrogen bonding between CO and NH groups (Between different chains); polypeptide chains can be parallel or antiparallel; polypeptide can make a beta-turn and fold back to run in opposite direction (Hydrogen bond at turn is 3 residues away)"
811
Primary vs. Secondary vs. tertiary vs. quaternary structure
Primary = amino acid sequence and location of disulfide bonds; Secondary = spatial arrangement of amino acids that are close together; tertiary = spatial arrangement of amino acids that are far from one another; quaternary = how various subunits associate with one another
812
leucine zipper
forms if 2 alpha-helices, each with 4+ leucine residues and located on separate proteins, come together through interdigetation of the leucine residues
813
Carbohydrate
An aldehyde or ketone group and 2+ alcohol functional groups
814
Ketoses vs. Aldoses
```
"Ketoses = monosaccharide (carbohydrate) with a ketone group; vs.
Aldoses = monosacchardie (carbohydrate) with an aldose group"
```
815
Most naturally occuring monosaccharides are ______ isomers
D isomer
816
D vs. L isomer of monosaccharides
L = hydroxyl group is to the left of the reference carbon (the chiral carbon furthest from the cabonyl carbon) vs. D isomer = hydroxyl group is to the right of the reference carbon
817
pyranoses and furanoses
pyranoses = cyclic sugar with a 6-membered ring; vs. furanoses = cyclic sugar with a 5-membered ring
818
alpha pyranose/furanose vs. beta
alpha = the -OH group at the anomeric carbon is on opposite side of ring as the -CH2OH; beta = the -OH group at the anomeric carbon is on the same side as the CH2OH
819
Anomeric Carbon
Alpha and Beta carbohydrates are anomers b/c they differ only in configuration - around C-1, which is thus the anomeric carbon
820
How are furanoses formed?
Oxygen atom from C-5 alcohol group reacts with ketone group (C-2)
821
How are pyranoses formed?
Oxygen from C-5 hydoxyl group reacts with carbonyl aton (C-1) to form 2 different diastereomers
822
Hemiacetal
Alcohol + aldehyde product
823
Hemiketal
Alcohol + ketone
824
Reducing Sugars
Carbohydrates that are capable of reducing the Ag+ ion to silver metal in Tollen's reagent and can reduce the Cu2+ ion in Benedict's reagent to give brick-red precipitate ---> b/c the sugar contains a free ketone or aldehyde group
825
What are oligosaccharides?
Relatively short chains of monosaccharides linked to one another by a glycosidic bond
826
What type of bond links monosaccharides together?
Glycosidic bonds
827
Sucrose - reducing or non-reducing?
Non-reducing
828
Show to name sugars?
"(1) Start with an ""O"" if an O-glycosidic bond (linked by an Oxygen)
(2) Name the first sugar - alpha or beta; L or D (D if natural); then name
(3) List the carbons participating in the bond (ex: 1->4)
(4) End with ""-ide"" if it is a reducing sugar"
829
lactose
dissacharide found only in milk - composed of galactose and glucose; reducing
830
Starch
dissarcharide - compsed of glucose and fructose); non-reducing
831
homopolysaccharides vs. heteropolysaccharides
homo = consist of just one type of monosaccharide; (hetero = consist of different types)
832
how is starch digested?
First by Alpha-Amylase enzyme in the mouth, then further by pancreatic-alpha-amylase
833
Lipids
Molecules that can readily dissolve in nonpolar solvents but are relatively insoluble in water
834
fatty acid structure
carboxylic acid with a hydrocarbon side chain
835
Triacylglycerol structure
Glycerol backbone + 3 fatty acids
836
Triacylglycerol melting point & saturation level
More saturated = better packing, so higher melting points
837
Structure of glycerophospholipid
2 Fatty acids esterfied to glycerol; contain a phosphate group; ampiphilic - nonpolar tails (fatty acid) and polar head (phosphate)
838
predominant lipid component of all bio membranes
glycerophospholipid (aka phosphoglyceride), a type of phospholipid
839
sphingolipids
lipids not based on a glycerol backbone, instead, are derivatives of amino alchohols
840
sphingosine
common sphingolipid derivative
841
ceramide
sphingolipid with fatty acid attached at C-2 via an amide bond
842
sphingomyelin
type of sphingosine (if posphocholine or phosphoethanolamine is attached to C-1 of ceramide); common in myelin sheaths
843
cerebroside
Sphingolipid with single monosaccharide attached to the C-1 of ceramide
844
what is one believed purpose of extended oligosaccharide residues on a ganglioside?
Molecule Recognition
845
where is cholesterol synthesized? What does it typically exist as?
In cytosol; typically exists as cholesterol ester
846
Plasma membranes - major lipid component
Cholesterol
847
Structure of cholesterol
Fairly rigid set of 4 fused nonpolar rings and a polar hydroxyl group (so slightly ampiphilic)
848
Where are steroid hormones synthesized?
In the mitochondria
849
How are steroid hormones synthesized
"(1) Begins with hydrolysis of cholesterol esters in cytosol
(2) Then, transport cholesterol into mitochondrian
(3) ACTH stimulates conversion of cholesterol to pregnelone
(4) pregnelone is then converted to progesterone (which is finally converted to cortisol, aldosterone, and testosterone - which is converted to estradiol)"
850
what does a nucleotide consist of
"(1) a Nitrogenous base
(2) a pentose sugar
(3) phosphoric acid"
851
Nucleotide vs. nucleoside
Nucleoside = nitrogenous base + pentose sugar; Nucleotide = nucleoside + 1 to 3 phosphate groups
852
Pentose sugars in DNA and RNA
in DNA: 2'-deoxy-D-ribose; in RNA: D-ribose
853
Structure of DNA and RNA
Backbone of alternating pentose sugars and phosphate groups -- nitrogenous bases are attached to the sugars
854
What links together nucleotides in DNA and RNA
phosphodiester linkages
855
Role of phosphoric acid in DNA and RNA:
"(1) Excellent buffering capacity -- b/c has 3 pKa values
(2) makes the backbone polar -- since the Hydrogen on the hydroxyl grop has a pKa of around 3, so phosphate in DNA and RNA has a negative charge."
856
DNA Structure: per single strand
Nitrogenous bases are connected to the sugar by a N-glycosidic linkage & the nucleotide units are connected by phosphodiester bonds --> both are formed by a dehydration rxn (so can be hydrolyzed
857
How are DNA strands connected
"through interactions with nitrogenous bases:
- base pairing: A and T can be paired through 2 hydrogen bonds & G and C can be paired by 3 Hydrogen bonds ---> the two strands wrap around eachother
- At the 5' end, have an unreacted Phosphate group and at the 3' end have an unreacted hydroxyl group"
858
Types of RNA
"(1) mRNA (messenger RNA) = RNA polymers that allow for the synthesis of proteins
(2) tRNA (transfer RNA) = bring amino acids to site of protein synthesis
(3) rRNA (ribosomal RNA) = help define the ribosome"
859
chromatin
complex of linear doubl stranded DNA and protein (histones) - found in the nondividing (interphase) cell; as cell prepares for division - will become highly organized into chromsomes
860
somatic cell
cells which aren't gametes; are diploid - have 23 pairs of chromosomes in humans
861
karotype
the characteristic size and shape of the chromosomes in metaphase
862
Classification of chromsomes based on centromere location
metacentric = centromere in the middle; acrocentric = very small p arm (centromere near end); submetacentric: p arm just a little smaller then q arm; telocentric = no p arm - centromere is on end
863
p and q arem of chromosomes
p = short end, q = long end
864
histones
most abundent type of protein associated with DNA; consist of a high percentage of Lys & Arg residues --> so can form electrostatic relationships with negatively charged DNA
865
linked & histones
linker = the region separating histones
866
nucleosome
defined by the association of histones with DNA; each nucleosome repeats ~every 200 pairs
867
Nonhistones
any protein that associates with DNA that isn't a histone. Is NOT basic - instead, is acidic (with a negative charge). Ex: RNA polymerase
868
Phases of interphase
(1) G1 phase (2) S phase (3) G2 phase
869
What happens in G1 phase of interpase
Growth phase; RNA and proteins are actively being synthesized
870
What happens during S phase of interphase?
All 46 strands of chromatin are duplicated --> get 92 sister chromatids (but only 46 chromosomes still); daughter centrioles are synthesized
871
What happens during G2 phase of interphase
Chromatin begins to condense and become tightly coiled; more growth
872
Phases of mitosis
(1) Prophase (2) Metaphase (3) Anaphase (4) Telophase
873
What happens during prophase of mitosis?
Centriole pairs move apart; microtubules radiate from each centriole pair - forming an aster; chromosome condensation completes
874
What happens during metaphase of mitosis?
Chromosomes align along equator of the cell - a region called the metaphase plate; nuclear envelope now completeley gone
875
What happens during anaphase of mitosis?
centromeres of each chromosome divide & the 2 sister chromatids move towards opposite ends; cytokinesis begins
876
What happens during telephase
undoing prophase - each chromosome begins to unwind, microtubules disappear, nuclear membrane begins to form; cytokinesis continues
877
cytokinesis
cleavage of 1 cell into 2 daughter cells; usually begins late anaphase; when complete - signals end of mitosis
878
Interphase in meiosis
Preceeds both Meiosis I and Meiosis II - the Interphase before Meiosis 2, though, doesn't have S phase (b/c don't get replication)
879
What happens in step 1: leptotene of Prophase I?
Replicated chromosomes have already started to condense - and now become visible (have 23 from mother and 23 from father)
880
What happens in step 2: zygotene of Prophase I?
Have synapsis: homologous chromosomes pair --> get tetrads; synaptonemal protein appears between pairing chromosomes and facilitates their union
881
What happens in step 3: pachytene of Prophase I?
Genetic recombination occurs through crossing over
882
What happens in step 4: diplotene of Prophase I?
Crossing over happens at chiasmata
883
Chiasmata
the site on chromosomes where crossing over occurs
884
tetrads
pairing of 2 homologous chromosomes - in preparation for crossing over
885
What happens in step 5: diakensis of Prophase I?
Chiasmata reaches ends of chromatids --- homologous chromosomes begin to separate and appear joined at ends; nuclear envelope breaks down
886
What happens in Metaphase I?
Homologous chromosomes align on the metaphase plate; microtubules from spindle apparatus attach to centromeres
887
centromeres vs. centrosomes vs. centrioles
Centromeres = point on chromosomes that is attached to the mitotic spindle (during mitosis/meiosis); centrioles = organelle involved in mitotic spindle formation - have a pair of them within the centrosome
888
What happens in anaphase I?
Microtubules pull apart the homologous chromosomes (But centromeres DON'T DIVIDE); pair of sister chromatids - known as a dyad - migrate to one end; cytokinesis begins
889
What happens during telephase I?
Dyads complete movement; cytokinesis more pronounced
890
Asexual reproduction happens in what type of organism (haploid or diploid)
Can happen in either haploid or diploids
891
3 Major components of eukaryotic biological membranes
(1) Glycerophospholipids; (2) Sphingolipids; (3) Cholesterol
892
Most abundant glycerophospholipid in the cell membrane?
phosphtidylcholine & phosphatidylethanolamine
893
Factors influencing membrane fluidity:
(1) Short fatty acid side chains = increased fluidity (2) more cis unsaturation = increased fluidity (3) Cholesterol: acts as a fluid buffer - at high temps, decreases fluidity, and at low temps, increases fluidity (4) increasing temp = increased fluidity
894
What are glycoproteins and glycolipids?
Carbohydrates on either the proteins embedded in the lipid bilayer of membranes or directly in the lipid bilayer of membranes; play important roles in cell recognition
895
The endoplasmic reticulum is single or double membraned
Double
896
functions of smooth endoplasmic reticulum
(1) Synthesizes lipids (for cell membranes, and secretory lipids) (2) metabolizes carbohydrates (3) Aids in detoxification of drugs and toxins
897
Functions of Rough Endoplasmic Reticulum
(1) Site of protein synthesis (for proteins secreted into extracellular environment, integral proteins, and proteins that remain in the ER, golgi, and lysosomes) (2) some post translational protein modification (such as forming disulfide bridges)
898
What are the lipid components of cell membranes?
(1) Phospholipids (and phosphatids) (2) Steroids (3) Waxes
899
What is the fluid mosaic model?
The model of a cell membrane: says membranes are made up of distinct components, which can move around
900
What are the factors affecting membrane fluidity
(1) Cholesterol = like a buffer: at high temps, it decreases fluidity; at low temps, it increases fluidity (2) More cis unsaturation (double bonds) = increased fluidity (3) Increased temp = increased fluidity
901
Simple vs. facilitated diffusion
Both are passive transport diffusion (down a gradient); simple = solutes move directly through lipid bilayers; facilitated = depend on interaction with membrane protein (a protein channel
902
Permeases
Protein channels
903
Types of Facilitated diffusion
(1) Uniport (1 molecule, 1 direction) (2) Symport (2 molecules, same direction) (3) Antiport (2 molecules, different directions)
904
What is a colligative property? Is osmosis a colligative property?
Depends on # of solute molecules, but not type of solute
905
Primary vs. Secondary Active Transport
Primary = directly uses ATP; Secondary = uses ionic gradient set up using energy
906
Sodium/Potassium Pump is called what (more formally) and is what type of pump?
Na+ K+ ATPase ---> active transport
907
Group Translocation
Type of used for sugar transport across membrane - sugar residue is phosphorylated as being transported through plasma membrane
908
Bulk Transport
Exocytosis or endocytosis
909
Types of endocytosis
Phagocytosis (if vesicle contains particulate matter); pinocytosis (if vesicle contains liquid portion of exctracellular matrix)
910
What are the defining characteristics of Eukarytoic Cells
(1) Membrane bound nucleus (2) Presence of Organelles (3) Mitotic Division
911
Nucleolus
Center of nucleus - compact and dense; site of ribosomal assembly (where rRNA is assembled with proteins to make a fully formed ribosome, which will be trafficked out into cytoplasm via nuclear pore)
912
Nuclear Pore
Transports across nuclear membranes (mRNA out, Protein in, etc.)
913
Nuclear Envelope
Combination of inner + outer membrane with the nuclear pores
914
3 Defining characteristics/functions of mitochondria
(1) Site of ATP production (2) Inner + outer membranes (3) Self-replicates
915
Mitochondria - outer membrane structure and permeability
Made of a lipid bilayer & permeable to small molecules
916
Mitochondria - inner membrane structure and permeability
Made of a lipid bilayer - folded into cristae (increased surface aea = more area for cellular replication) & impermeable; also, studed with Electron Transport Chain Enzymes
917
Mitochondrial Matrix
center (inside of inner membrane) of mitochondria
918
Steps to Cellular respiration
(1) Glycolysis (2) Pyruvate Dehydrogenous Complex (PDC) turns pyruvate into acetyl-CoA (3) Krebs Cycle turns Acetyl-CoA into NADH and FADH2 (e- carriers) (3) ETC - makes ATP using NADH and FADH2
919
Where in cell does glycolysis occur
In cytoplasm (only step of cellular respiration that doesn't occur in mitochondria)
920
Where is the Pyruvate Dehydrogenase Enzyme
In the Mitochondrial Matrix
921
Where does the Krebs cycle take place
Mitochondrial Matrix
922
Where does the ETC take place?
In inner mitochondrial matrix
923
What is the lysosome
Membrane bound vesicles containing acid hydrolase enzymes; digests molecules and substances - and releases building blocks into cytoplasm
924
Which proteins are synthesized in the cytoplasm vs. the Rough ER
Cytoplasm - proteins that will end up in: nucleus, mitochondria, peroxisomes, cytoplasm; Rough ER, proteins - secreted into extracellular environment, integral membrane proteins, or proteins for lysosomes, ER, golgi
925
What is the secretory pathway
(1) All proteins being translation in the cytoplasm (2) Proteins marked for secretory pathway have a signal sequence - detected early on, pushes protein to rough ER, where translation is finished (3) Protein butts off in vesicle from Rough ER (4) Vesicle merges with Golgi apparatus, protein is released into Golgi where it is modified (5) Vesicle containing protein breaks off from Gogli (6) Veiscle with protein goes to membrane (where it is secreted or becomes part of membrane) or lysosome
926
3 Functions of Golgi Apparatus
(1) Modifies Proteins made in Rough ER (2) Sorts and sends proteins to proper destination (3) Synthesizes certain molecules that needs to be sorted
927
structure of golgi apparatus
Groups of sacks stacked together (cis stack = closest to rough ER; medial stack = in middle; trans stack = further from ER)
928
Peroxisomes
Organelles that collect peroxides & break them down (has a catalase enzyme) into water and oxygen
929
Functions of cytoskeleton
(1) Structural Support (2) Movement (3) Transport
930
Microfilaments - composition & functions
Composition = actin polymers twisted around; Functions = cleavage (such as in cytokinesis) and cellular contractions
931
Intermediate filaments - composition & function
Composition = many different proteins form polymers & wrap around; Function = structural support (resist mechanical stress)
932
Microtubules - composition
alpha-tubulin + beta-tubulin dimer -- forming a sheet --- forming a tube; one side is anchored to a microtubule organizing center and the other is dynamic (can grow)
933
types of MTOC (Microtubule Organizing Systems
(1) Centrosome (2 centrioles which are made up of microtubules & form mitotic spindle - in metaphase) (2) Basal Bodies (Attach to flagella or cilia, enabling them to move)
934
9+2 Arrangement
Structure of cillia and flagella - have 9 pairs + 1 pair in center of microtubules; nexin (protein) in between pairs and dynein (protein) coming out of microtubules - which breaks down ATP & helps mitochondria move past eachother, moving cillia/flagella
935
"Railroad Track" in neurons
formed by microtubules - with kinesis and dynein - help shuttle compounds/vesicles/etc. from one end of neuron to other (can go both ways)
936
Function: Microfilaments vs. intermediate filaments vs. microtubules
Microfilaments = cleavage & contractility; Intermediate filaments = structural support; Microtubules = (1) Mitotic Spindles (2) Cillia/Flagella mvmt (3) Railroad track in neurons
937
composition of flagella: eukaryotes vs. prokaryotes
eukaryotes: made of microtubules; prokaryotes: made of flagellin protein
938
composition of cilia:
(only found in eukaryotes) made of microtubules
939
Cell division: eukaryotes vs. prokaryotes
Eukaryotes: mitosis; prokaryotes: binary fission
940
Cell Theory
(1) Cell is the basic structure of life (2) All living things are made of cells (3) All cells come from previous cells
941
Prokaryotic Domains
(1) Archae (2) Bacteria
942
Major classifications of bacteria
(1) Bacilli (rod-shaped) (2) spirilli (spiral-shaped) (3) Cocci (spherical-shaped)
943
Defining characteristics of prokaryotes
(1) Lack of nuclear membrane (2) Lack of mitotic apparatus (3) Lack of typical eukaryotic organelles (4) Presence of cell wall (in bacteria)
944
Size of ribosome in eukaryotes & prokaryotes
Eukaryotes: 80S (made up of 60S + 40S); Prokaryotes: 70S (50S + 30S)
945
Bacteria: aerobic or anaerobic
There are both anaerobic and aerobic bacteria
946
Bacteria growth
exponential (until run out of food, etc.)
947
Nucleoid
region containing the circular double-stranded DNA chromosome in bacteria
948
Plasmid
extragenomic DNA that some bacteria have (could allow drug resistance)
949
chemotaxis
Why bacteria move - by attraction towards or away from certain chemicals
950
How and why do bacteria move
How: flagella; why: chemotaxis
951
Gram positive vs. gram negative bacteria
Gram positive (stain blue) - have one thick peptidoglycan cell wall just outside of plasma membrane; Gram Negative (stain pink) - have one thin peptidoglycan layer (in between membranes) AND an outer cell membrane made of lipopolysaccharides and porins
952
transformation & conjugation
transformation = uptake of genetic material (by bacteria) from the surrounding medium; conjugation = transfer of genetic info by cell-cell contact
953
Transduction
Transfer of bacterial genes by viruses
954
Transposons
(in eukaryotes and prokaryotes) DNA sequence that can change its position within a genome (can alter code); in bacteria - antibiotic resistance plasmids can be conjugated via transposons onto other bacteria
955
aster
describes the star shaped structure around the Centrioles during mitosis; Astral microtubules = the microtubules branching off from it (don't connect to kinetochores)
956
Virus structure
Nucleic Acid + surrounded by protein coat
957
Virus Capsids vs. Nucleocapsid
If no nucleic acid in the shell = capsid; if has nculeic acid in the shell = nucleocapsid
958
Enveloped vs. Non-enveloped viruses
Enveloped = enveloped by lipid membraned (derived from host cells) attached to nucleocapsid by matrix proteins
959
Genome of viruses
Can be RNA or DNA; single stranded or dobule stranded
960
Positive and negative strands in Viruses
mRNA template = + strand. If DNA/RNA has identical sequence, then it is also +, if not, then it is -.
961
Organelles and nucleus in virus
Don't have either
962
Bacteriophage structure
Head (contains nucleic acid); tail; tail fibers; spikes
963
Intercepts in Lineweaver Burke Plot
X = -1/Km; Y = 1/Vmax
964
AMP, ADP, and ATP Structure
"Adenine (Purine Ring) + Ribose (5 Carbon Sugar), attached via a N-Glycosidic or N0Acetyl Linkage;
-For AMP, also have 1 Phosphate (via a phosphomonoester linkage to 5' Carbon); -For ADP have a 2nd phosphate (via acid anhydride linkage); -For ATP have a 3rd phosphte"
965
N-Acetyl linkage + N-Gylcosidic linkage
(same thing) connects C1' of ribose and N9 of Nitrogen
966
Nicotinamide Adenine Dinucleotide:
NAD; a coenzyme with 2 phosphorylated adenosine moieties
967
What enzyme enables humans to synthesize the nicotinamidd portion of NAD
tryptophan
968
Flavin Mononucleotide
FMN; the active coenzyme - when riboflavin (aka Vit B2) is phosphorylated
969
FAD
If add Phosphate + Ribose ring + Adenine to FMN; a coenzyme
970
Coenzyme A
An important coenzyme; -sulfhydrol group is active site; -acyl groups can attach to sulfhydryol to form acetyl-coenzyme A
971
Most important regulator in glycolysis
"PFK1:
- inhibited by high ATP, H+, and Citrate
- stimulated by high AMP"
972
How do disacchardes enter the glycolytic pathway?
"Must first be hydrolyzed into monosaccharides.
| Ex: maltose is hydrolyzed by maltase into 2-beta-D-glycopuranose which can enter glycolysis"
