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Biochemistry/Physiology > Quiz 2 - Membranes, RMP, AP, Muscle Physio, Capillary Permeability, Basic Cell Bio > Flashcards

Quiz 2 - Membranes, RMP, AP, Muscle Physio, Capillary Permeability, Basic Cell Bio Flashcards

(77 cards)

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1
Q

Permeability of molecules from high to low

A

Hydrophobic molecules > Small uncharged polar molecules > Large uncharged polar molecules > Ions O2 > Glycerol > Glucose > Cl-, K+, Na+

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2
Q

Peripheral Proteins

A

Adhere only temporarily to the membrane, usually to an integral protein

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3
Q

Integral protein

A

Incorporated into the lipid bilayer of the membrane

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4
Q

Amphitrophic protein

A

exist both as water soluble and lipid bound proteins

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5
Q

Fluid Mosaic Model

A

Idea that proteins and lipids move laterally through the membrane freely. Modified by discovery of lipid rafts.

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6
Q

Asymmetric distribution of phospholipids in PM

A

Different types of phospholipids are found in uneven ratios between inside and outside of membrane. The composition of a membrane changes depends on cell needs and functions

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7
Q

Examples of integral proteins

A

G-Protein Coupled Receptors have multiple transmembrane portions. Bacterial Rhodopsin does too.

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8
Q

Lipid-linked membrane proteins

A

Lipid chains can link proteins to the cell membrane

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9
Q

Cholesterol and membrane flexibility

A

Typically Cholesterol decreases the flexibility of the membrane, but association with different proteins can increase the flexibility

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10
Q

Effect of heat on bilayers

A

Produces thermal motion of side chains (disorganization), but bilayer maintains integrity. % of particular fatty acid ratio changes based on temperature (physiological and metabolic status)

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11
Q

Lateral diffusion of lipids/proteins

A

Uncatalyzed, very fast and spontaneous

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12
Q

Flippase

A

Catalyzes flipping a phospholipid from outside to inside the membrane.

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13
Q

Floppase

A

Catalyzes flopping a phospholipid from inside to outside the membrane.

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14
Q

Scramblase

A

Catalyzes switching sides of two phospholipids in and out of the membrane.

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15
Q

Lipid Raft

A

Regions of membrane that are thicker, enriched in sphingolipids and cholesterol that compartmentalize cell functions. Bounded by calveolins

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16
Q

Calveolins

A

Proteins involved in the endocytosis of proteins and lipid rafts

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17
Q

Ionophore

A

Membrane vesicle that transports ions through membranes

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18
Q

Current

A

Flow of electrical forces down a gradient (ions flowing through channel in/out of cell)

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19
Q

Voltage

A

Potential difference (ion gradient)

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20
Q

Resistance

A

Opposition to passage of current (Membrane. Ion channels alter resistance)

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21
Q

Resting Membrane Potential

A

Electrical voltage potential of a resting cell. -70mV to -90mV

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22
Q

Nernst Equation

A

Mathematical relationship between difference in ion concentration and the voltage across the membrane at equilibrium

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23
Q

Local Potential

A

Localized alteration of membrane potential (ex. ion channel opening from ligand binding)

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24
Q

Propagated/Action Potential

A

Change in potential that travels along membrane

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25
Na+ and K+ relative concentrations
Na+ high outside of cell, K+ high inside cell
26
Action potential Initiation
Opening of Na+ channels allows Na+ to flow in, depolarizing the cell up to around +30 mV
27
Action potential Propagation
Depolarization from Na+ channel triggers opening of voltage-gated Na+ channels down the axon, relaying the AP
28
Action Potential Repolarization
Na+ channels close and inactivate, K+ channels open and allows K+ to rush out, repolarizing the cell back to around -70 mV.
29
Absolute refractory state
Na+ channels are inactivated and cannot be restimulated no matter how strong the stimulus
30
Relative refractory period
Na+ channels are reactivated and can react to stimulus, but because K+ channels are still open and repolarizing the cell, a stronger than normal stimulus is required to depolarize again during this time
31
Na+/K+ Pump
3 Na+ out, 2 K+ in, utilizing ATP to restore concentration gradient.
32
What does "All-or-nothing" mean in relation to action potentials?
APs either fire or don't. Once a stimulus crosses the threshold, it fires. The strength of the stimulus does not change the amplitude of the action potential
33
Hyperkalemia
High extracellular K+ concentration. Reduces gradient for K+ out, leads to less resistance to depolarization. (Ex. poor kidney function)
34
Hypokalemia
Decreased EC K+ concentration, increases gradient for K+ out, leads to more resistance to depolarization. (Ex. bad diarrhea)
35
Cardiac muscle APs
Voltage-gated Ca2+ channels open to prolong depolarization. Excess Ca2+ can effect excitability in opposite way than K+ by charge screening
36
Neuromuscular junction
Site where a motor nerve unit innervates a muscle fiber
37
Motor unit
Alpha motor neuron and all muscle cells it innervates. Each muscle fiber connected to only one alpha neuron
38
Sarcoplasmic Reticulum
Stores Ca2+ in terminal cisternae and releases it through ryanodine receptors
39
Transverse tubules
small tubes that propagate action potentials
40
Sarcomere I and H zone shorten during contraction
41
Excitation-Contraction Coupling
42
Creatine Phosphate
Stores energy to synthesize ATP. Stored energy for 15 seconds of muscle use
43
Anaerobic respiration
Glucose-1-Phospage broken down into lactic acid to release 2 ATP. Good for 30-45 seconds of muscle use
44
Aerobic respiration
Citric acid cycle and electron transport chain create 38 ATP per glucose. Fuels muscles for hours.
45
Isotonic contraction
Tension generated by muscle is greater than load, muscle shortens
46
Isometric contraction
Load is greater than max tension and muscle doesn't shorten.
47
Phases of muscle twitch
Stimulus Latent period - 2 msec delay Contraction - tension develops Relaxation - Loss of tension, return to rest length Refractory - period when muscle fiber won't respond
48
"All-or-none" motor unit response
Motor unit fires when action potential is received
49
Fractionation
As more motor units are recruited, the tension gets greater
50
Henneman's Size Principle
Motor units recruited from smallest to largest. Type 1/Slow twitch - always firing, smallest, used in light intensity exercise Type II/Fast twitch - become recruited when needed.
51
Multiple Motor Unit Summation (Recruitment)
Increasing the strength of a stimulus recruits additional motor units
52
Wave/Temporal Summation
Increasing frequency of stimulus leads to tetanus
53
Treppe
"Staircase" summation, right before tetanus
54
Muscle Spindles
Proprioceptors sensitive to muscle length and tendon. Stretch reflexes activated when muscle spindles recognize stretch. Stimulates stretched muscle to contract
55
Reciprocal inhibition
Reciprocal innervation inhibits opposing muscles to contract when a stretch reflex is activated
56
Extrafusal fibers
Bulk of muscle, innervated by alpha-motor neurons, provide force for contraction
57
Intrafusal fibers
Encapsulated in collagen sheaths to form muscle spindle. Innervated by gamma-motor neurons and Group Ia and II sensory afferents Nuclear Bag fibers - detect fast, dynamic changes in muscle length and tension Nuclear Chain fibers - detect static changes in length and tension
58
Golgi Tendon Reflex
Initiated by Golgi Tendon Organs (GTOs) that detect tension in tendons. Inhibits alpha-motor neurons to relieve tension in the tendon. Protective feedback mechanism to prevent tendon damage.
59
Diffusion
Movement of nutrients, O2, CO2, lipid soluble substances through capillary wall down concentration gradient
60
Bulk Flow/Ultrafiltration
Movement of protein free extracellular fluid in and out through water-filled pores
61
Vesicular Transport
Translocation of macromolecules across capillary endothelium. Ex.) Pinocytosis
62
Hydrostatic Pressure
Force directed out of the capillary by fluid pushing against capillary wall. Higher in arteries than in capillaries, lower in veins. Driven by heartbeat.
63
Crystalline Osmotic Pressure
Oncotic pressure due to small molecules in plasma. Since water soluble molecules have concentrations = on both sides of capillary, has no effect on water flow.
64
Oncotic pressure/Colloid osmotic pressure
Osmotic pressure exerted by plasma proteins (Albumin), pulls water back into capillary
65
Starling Law
Net Filtration Pressure = Net force out - Net force In Net force out = Capillary hydrostatic pressure + Osmotic pressure due to intersticial fluid protein concentration Net force in = Interstitial fluid hydrostatic pressure + Oncotic pressure due to protein concentration
66
Velocity of blood flow
Highest in arteries Slowest in capillaries Middle in veins
67
Cross-sectional area of blood vessels
Low in arteries in veins High in capillaries
68
Vascular shunts/Metarteriole
Throughfare channel connecting an arteriole directly with a postcapillary venule.
69
Precapillary sphincter
Cut off smooth muscle that surrounds each true capillary and regulates blood flow into the capillary in response to vasomotor (sympathetic) nerves, to bypass or enter capillaries.
70
Big Picture of Capillary fluid movement
Outward movement of 20 L of fluid arterial side Inward movement of 17 L of fluid venous side 3 L of fluid enters Lymphatic system
71
Lymphatic Capillaries
Blind ended sacs in interstitial space that abosrb lymph fluid. Low pressure, wider than capillaries
72
Pinocytosis
Bulk flow transport of fluid into or out of capillary lumen via vesicles
73
Prokaryotic Cells
Smaller, have cell wall, no membrane bound organelles, cytoplasmic DNA, nucleoid, no cytoskeleton, smaller ribosome, replicate through binary fission, genetic diversity through mutation
74
Eukaryotic Cells
Larger, no cell wall, membrane-bound organelles, Nuclear DNA, nucleus, cytoskeleton, larger ribosome, replicate through mitosis, genetic diversity through meiosis/recombination
75
Gram-positive bacteria
Stain purple, have glycoprotein and peptidoglycan cell wall
76
Gram-negative bacteria
Stain red, have peptidoglycan, outer membrane and lipopolysaccharide cell wall
77
Cytoskeleton
Microfilaments, microtubules, intermediate filaments

Biochemistry/Physiology (10 decks)

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