Membranes & Proteins Unit: Textbook & Article Notes Flashcards
(128 cards)
1
Q
(ch 6) metabolism is all … that occur in a cell
A
chemical reactions
2
Q
(ch 6) … reactions release energy, where … reactions absorb energy
A
exergonic; endergonic
3
Q
(ch 6) many reactions in the body are… (e.g. protein synthesis, nerve conduction, muscle contraction)
for these to occur, they have be coupled with … reactions
A
endergonic; exergonic
4
Q
(ch 6) enzyme: protein that functions to … without itself being affected by the reaction
allow reactions to occur under … conditions
regulate …, partly by eliminating ….
A
speed a chemical reaction; mild; metabolism; nonspecific side reactions
5
Q
(ch 6) not all enzymes are proteins
example: …, which are made of …, act in synthesis of RNA and proteins at ribosomes. biological catalysts
A
ribozymes
6
Q
(ch 6) metabolic pathways; reactants for first reaction converted into …, and these act as the … for the next reaction until the final product is attained
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products; reactants
7
Q
(ch 6) one metabolic pathway can interact with several others, because different pathways have several …
A
molecules in common
8
Q
(ch 6) energy of activation: energy that needs to be … to cause molecules to …
prevents molecules from spontaneously …
enzymes … this
A
added; react with one another; degrading in a cell; lower
9
Q
(ch 6) metabolic pathways are useful for …/…. small increments of molecular energy. they also allow cells to … and … changing environmental conditions
A
releasing; capturing; regulate; respond to
10
Q
(ch 6) reactants in enzymatic reactions are called the … for that enzyme
A
substrates
11
Q
(ch 6) most times, only one small part of the enzyme, the … site, associates directly with the substrate
in this site, the enzyme and substrate are positioned such that they easily fit together. the site undergoes a slight … to accommodate the substrate –> … model
A
active; shape change; induced fit
12
Q
(ch 6) enzymes are not … by the reaction, but some may … in the reaction (e.g. trypsin breaks down … in digesting proteins0
A
used up; participate; peptide bonds
13
Q
(ch 6) specificity of enzymes allows for
A
metabolic regulation
14
Q
(ch 6) presence of some enzymes helps determine which metabolic pathways are
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operative
15
Q
(ch 6) rate of reaction: amount of …/ ….
A
product produced; unit time
16
Q
(ch 6) increasing amount of … and … can increase reaction rate
A
substrate; enzyme
17
Q
(ch 6) any factor that alters active site shape can … reaction rate
A
decrease
18
Q
(ch 6) cofactors: additional molecules that help … by helping to … or participate int he reaction
A
speed the reaction rate; bind the substrate to the active site
19
Q
(ch 6) since reactions are dependent on collisions, more substrate leads to more collisions between … which then allows more .. to be …
A
enzymes; product; formed quickly
20
Q
(ch 6) there is a point at which the maximum … is achieved
A
reaction rate
21
Q
(ch 6) at respective pH values, enzymes can maintain normal … which allows for optimal function –> optimal pH is where … is highest
A
structural configuration; reaction rate
22
Q
(ch 6) when temps increase, enzyme activity …, because more …. between enzymes and substrates occur
A
increases; effective collisions
23
Q
(ch 6) if temps are too high, … occurs
A
denaturation
24
Q
(ch 6) most enzymes need an inorganic ion/nonprotein organic molecule at active site to work properly –> …
e.g. Cu, Zn, Fe –> inorganic ions
nonprotein organic molecules are …
A
cofactors; coenzymes
25
(ch 6) vitamins are small organic molecules that are required in trace amounts for
synthesis of coenzymes
26
(ch 6) vitamins become part of a coenzyme's .... if it is not available, enzymatic activity will ... and a ... arises
molecular structure; decrease; vitamin deficiency
27
(ch 6) enzyme inhibition: when a molecule binds to an enzyme and ... its activity, occurs when sufficient ... is present
decreases; end product
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(ch 6) noncompetitive inhibition: inhibitor binds to the enzyme at location other than ... this site is the ...
active site; allosteric site
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(ch 6) when an inhibitor is at the allosteric site, the active site ...
changes shape
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(ch 6) competitive inhibition occurs when inhibitor and substrate compete to ...
helps to regulate ....
enzyme inhibition is usually ...., as the enzyme normally doesn't get damaged
bind to active site; amount of product; reversible
31
(ch 34) digestion of food in humans is an ... event
extracellular
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(ch 34) mechanical digestion involves the ... of food into smaller particles
physical breakdown
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(ch 34) chemical digestion requires ... secreted by ... or by ..., which break down particular macromolecules into smaller molecules that can be absorbed
enzymes; digestive tract; accessory glands
34
(ch 34) mouth- ..- is the beginning of the digestive tract
oral cavity
35
(ch 34) palate: ... of the mouth, separates the ... from the ...
... palate and ... palate
roof; oral cavity; nasal cavity; anterior hard; posterior soft
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(ch 34) uvula: posterior extension of the
soft palate
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(ch 34) 3 major pairs of salivary glands send ... by way of ... into the mouth
juices; ducts
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(ch 34) ... is typical end product of salivary amylase digestion
maltose
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(ch 34) while in the mouth, food is manipulated by the muscular ..., which has ... and ... receptors
tongue; touch; pressure
40
(ch 34) tongue also has ..., sensory receptors that are stimulated by the ... of food
taste buds; chemical composition
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(ch 34) tongue composed of ... muscle and an outer layer of ... membrane mixes chewed food with saliva, forming bolus in preparation for ...
striated; mucous; swallowing
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(ch 34) pharynx: passageway where food is ..., the ... and ... passages come together here and then separate
swallowed; digestive; respiratory
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(ch 34) esophagus: tubular structure of about ... cm in length that takes food the stomach; passageway where ... pushes food to stomach
25; peristalsis
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(ch 34) sphincters: muscles that ... and act as ...
| tubes close when sphincters ... and open when sphincters ...
encircle tubes; valves; contract; relax
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(ch 34) lower gastroesophageal sphincter located where esophagus enters the ... when food enters, the sphincter ... for a few seconds and then closes again
stomach; relaxes
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(ch 34) heartburn occurs due to acid reflux, when some of the stomach's contents escape into the
esophagus
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(ch 34) when vomiting occurs, abdominal muscles and the diaphragm (muscle that separates thoracic and abdominal cavities)
contract
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(ch 34) when food is swallowed, soft palate moves back to close off they
nasopharynx
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(ch 34) epiglottis: flap of tissue covering the ...-- opening into the ..
glottis; trachea
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(ch 34) bolus moves through the pharynx into the esophagus because
air passages are blocked
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(ch 34) lumen: ... space of digestive tract where food passes as it is digested
central
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(ch 34) wall of digestive tract consists of 4 layers:
innermost: mucosa- type of mucous membrane, produces .. .to protect the wall from ... inside the lumen
second layer: submucosa- loose connective tissue that contains ..., ..., ..., and ...
third layer: muscularis- contains 2 layers of smooth muscle; inner, circular layer encircles the tract and the outer, longitudinal layer lies in the same direction as the tract. contraction of these muscles, under ... nervous control, accounts for the movement of the gut contents from esophagus to the rectum by ...
fourth layer: serosa- secrets watery fluid that lubricates outer surfaces of the digestive tract and reduces ... between organs
mucus; digestive enzymes; blood vessels; lymphatic vessels; nerves; lymph nodules; involuntary; peristalsis; friction
53
(ch 34) wall of the stomach has deep folds, ...., that disappear as the stomach fills to capacity (about ...)
rugae; 1 L
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(ch 34) muscular walls of the stomach contract vigorously and ... with ... secreted whenever food enters the stomach
mix food; juices
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(ch 34) epithelial lining of the stomach has millions of ... which lead to ... that produce ...
gastric pits; gastric glands; gastric juice
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(ch 34) gastric glands produce so much HCl that stomach has a typical pH of about ...
usually kills bacteria and other microorganisms
stops activity of ..., which functions in near-neutral pH
2.0; salivary amylase
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(ch 34) chyme's entrance into small intestine sets off a neutral reflex that causes pyloric sphincter to vigorously contract and close temporarily--> slow manner in which chyme enters small intestine allows for
thorough digestion
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(ch 34) bile emulsifies fat- causes fat to
disperse in water
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(ch 34) small intestine has slighly ... pH due to presence of ..., which neutralizes chyme
basic; sodium bicarbonate
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(ch 34) small intestine has a large surface area due to ...- fingerlike projections that have an outer layer of columnar epithelial cells, which have thousands of microscopic extensions called ...
villi; microvilli
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(ch 34) microvilli hold ..., called ...
| also increase the ... of the villus, which allows for ... of nutrients
intestinal enzymes; brush-border enzymes; surface area; absorption
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(ch 34) sugars & amino acids enter villus blood capillaries. glycerol and fatty acids enter the epithelial cells of the villi, and in these cells they are joined and packaged as ..., which enter ...
lipoprotein droplets; lacteals
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(ch 34) after nutrients are absorbed, they are carried to all cells via the
bloodstream
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(ch 34) large intestine absorbs ..., ..., and some ..
water; salts; vitamins
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(ch 34) large intestine stores .. until elimination
indigestible material
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(ch 34) appendix thought to serve as reservoir for ... that help maintain intestinal health
good bacteria
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(ch 34) about 1.5 L of water enters digestive tract daily due to eating/drinking, an additional 8.5 L from carrying substances secreted by digestive glands. 95% of this is absorbed by ..., most of rest by ..
small intestine; colon
68
(ch 34) if water is not reabsorbed, ...occurs, potentially causing severe ... and ... loss
diarrhea; dehydration; ion
69
(ch 34) symbiotic bacteria live in colon that protect against more ... of bacteria and produce ... such as ... (necessary to ...)
pathogenic species; vitamins; vitamin K; blood clotting
70
(ch 34) feces consists primarily of.., intestinal ..., and also has undigested ..., ..., ... products (e.g. bile pigments), ... material, ..., and dead ... from intestinal lining
water; bacteria; plant material; fats; waste; inorganic; mucus; cells
71
(ch 34) pancreas has endocrine and exocrine functin:
endocrine: section of ... and ... for blood glucose regulation
exocrine: ... juice, which contains NaHCO3 that neutralizes acid chyme, ... which digests starch, trypsin digesting protien, and lipase for fat
insulin; glucagon; pancreatic; pancreatic amylase
72
(ch 34) liver is largest ... in the body
gland
73
(ch 34) liver removes and metabolizes .. substances from blood, removes and stores .. and ..., makes many of the ... found in blood plasma and helps regulate quanitity of ... in blood, maintains blood ... levels, forms ..., produces ... which is stored in the ...
toxic; iron; vitamisn; proteins; cholesterol; glucose; urea; bile; gallbladder
74
(ch 34) emulsifying fat provides a much larger ... that can be acted upon by lipase
surface area
75
(ch 34) excess ... stored in gallbladder; when it is needed, gallbladder contracts, releasing it into the duodenum via the ...
bile; common bile duct
76
(ch 34) protein digestion begins in the
stomach
77
(ch 34) enzyme trypsin secreted as ..., which is converted to trypsin in the ...
trypsinogen; duodenum
78
(ch 34) maltase and peptidases are enzymes that complete ... into glucose and amino acids, respectively
starch and protein digestion
79
(ch 34) lipase generates end products of ... and ..., which enter villi and are rejoined and packaged as lipoprotein droplets which enter lacteals
glycerol; 3 fatty acids
80
(ch 34) fiber includes various indigestible carbs from plants
adds ... to fecal matter, stimulating ... in the colon, preventing ... and keeping you ... longer
soluble fiber prevents ... and ... from being absorbed and therfroe protects against heart disease
bulk; movement; constipation; feeling full; bile acids; cholesterol
81
(ch 34) vitamins are organic compunds that regulate various metabolic activities. many are part of ...
minerals: 20 elements needed for various ... functions, such as regulation of biochemical reactions, maintenance of fluid balance, and incorporation into certain structures and compounds
coenzymes; physiological
82
(ch 5) junctions between cells allow for
coordinated behavior
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(ch 5) adhesion junctions: mechanical attachment of two adjacent cells
desmosomes: internal cytoplasmic plaques attached to intermediate filament cytoskeleton within cell. joined by ... called cadherins beween cells
integral membrane proteins
84
(ch 5) desmosomes: sturdy but flexible sheet of cells, present in some ... where tissues get .. (e.g. heart, stomach, bladder)
organs; stretched
85
(ch 5) hemidesmosome: intermediate filaments of cytoskeleton are attached to the ... through integrin proteins
ECM
86
(ch 5) ... junctions are the most common type of intercellular junction between cells
adhesion junctions
87
(ch 5) tight junctions: a type of adhesion junction that bring cells even closer together than desmosomes
connect ... between adjacent cells
tissues that serve as ... are held together by these (e.g. in intestine to prevent digestive juices from reaching the rest of the body, and in the kidney, to keep urine within the tubules)
plasma membranes; barriers
88
(ch 5) gap junctions: allow for ..., formed when two identical ... join
lends ... to the cells, but allows ... and ... to pass between them
important in heart and smooth muscle because it allows flow of ions required for cells to ... as a unit
cellular communication; plasma membrane channels; strength; small molecules; ions; contract
89
(ch 5) cytoplasm of living plant cells connected by ... --> narrow, membrane-lined channels that pass through the ...
plasmodesmata; cell wall
90
(ch 5) cytoplasmic strands within plasmodesmata allow direct ... of some materials between adjacent plant cells and eventually ... all the cells in a plant
allow only ... and small ... to pass freely from cell to cell, meaning that plant cells can maintain their own concentrations of larger substances and differentiate into particular cell types
exchange; connect; water; solutes
91
(ch 31) negative feedback is the primary homeostatic mechanism that keeps a variable close to a ...../...
particular value; set point
92
(ch 31) two components to negative feedback (and feedback in general): ... and ...
sensor; control centor
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(ch 31) sensor detects a ... in internal environment
| control center initiates an ... to bring conditions back to normal --> sensor is ... when normal conditions are reached
change; action; deactivated
94
(ch 31) negative feedback is present when the output of the system ... initial stimulus
e.g. blood pressure rising, receptors signal a control center that stops sending nerve impulses to arterial walls, causing them to ...
dampens; relax
95
(ch 31) regulation of body temp (sensor and control center located in ...)
above normal temp: blood vessels of skin ..., more blood flows near the body's surface, where heat is ... to the environment; nervous system activates ... --> ...
below normal temps: blood vessels of skin ..., conserving ...; nerve impulses to ... for ..., which generates heat
hypothalamus; dilate; lost; sweat glands; evaporative cooling; constrict; heat; skeletal muscles; shivering;
96
(ch 31) positive feedback: mechanism that brings about a continually greater change in the ...
same direction
97
(ch 31) example of positive feedback:
head of baby begins pressing against cervix, stimulating sensory receptors --> nerve impulses reach the brain, causing pituitary gland to secrete ..., a hormone that travels in the blood and causes the uterus to ..., cervix is increasingly stimulated, strengthing ... until birth occurs
oxytocin; contract; uterine contractions
98
(ch 31) positive feedback can be .. (e.g. when a fever causes metabolic changes that push it even higher)
other examples of positive feedback: blood ..., stomach's digestion of...
harmful; clotting; protein
99
(ch 40) endocrine system largely composed of ... that secrete ... carried by the ... to target cells --> leads to ... effect (... but ... response)
glands; hormones; bloodstream; longer lasting; slower; prolonged
100
(ch 40) exocrine glands secrete products into ..., taking them to ... of other .../... of the body
ducts; lumens; organs; outside
101
(ch 40) endocrine glands secrete products into the ..., delivering them throughout the body
bloodstream
102
(ch 40) hormones are chemical signals that are a means of ... between cells, body parts, and even individuals
communication
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(ch 40) only certain cells, called ... cells, can respond to a specific hormone --> these carry ... for that hormone
target; receptor proteins
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(ch 40) pheromones: chemical signals that influence the
behavior of other individuals
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(ch 40) peptide hormones: peptides, proteins, glycoproteins, and modified amino acids
steroid hormones: all have same molecular complex of four C rings because they all derive from
cholesterol
106
(ch 40) action of peptide hormones:
when first messenger binds to receptor, a ... such as cAMP is formed
cAMP activates a ... enzyme, which activates another enzyme --> .../... ...
enzymes are activated through ...
second messenger; protein kinase; signaling/enzyme cascade; phosphorylation
107
(ch 40) action of steroid hormones: only produced by adrenal cortex, ovaries, and testes
do not bind to plasma membrane receptors, but rather, ... the cell due to lipid nature. once inside, they bind to ..., usually in the ... but sometimes in the ...
enter; internal receptor; nucleus; cytoplasm
108
(ch 40) action of steroid hormones: hormone-receptor complex binds with ... and activates certain ..., mRNA moves to ... and ... occurs
DNA; genes; ribosomes; protein synthesis
109
(ch 40) steroids act more slowly than peptides because it takes more time to synthesize new proteins than to activate enzymes that are already present in cells, BUT: ..., more ... effects
longer; far-reaching
110
(ch 37) an electrical potential difference across a membrane is called the
membrane potential
111
(ch 37) resting potential, -70 mV, membrane potential when axon is not conducting an ..., inside of the neuron is more ... than outside
higher concentration of ... outside of the axon and higher concentration of ... inside of the axon
impulse; negative; Na+; K+
112
(ch 37) in myelinated axons, gated ion channels that produce an action potential are concentrated at the
nodes of Ranvier
113
(ch 37) saltatory conduction: action potential
jumps from node to node
114
(ch 37) when an action potential has moved on, previous node undergoes a refractory period --> sodium gates ...
action potentials cannot move ..., always moving down an axon toward its ...
unable to open; backward; terminals
115
(ch 37) intensity of a signal is determined by the amount of ... generated within a given time span
nerve impulses
116
(ch 37) axon terminal: fine ending with a small swelling at end of axon, lie close to dendrites of another neuron, region of proximity:
synapse
117
(ch 37) transmission across a synapse is carried out by ..., stored in ...
neurotransmitters; synaptic vesicles
118
(ch 37) when impulses reach an axon terminal, gated channels for ... open, and ... enters the terminal, stimulating ... of neurotransmitters which then bind to .. on postsynaptic membranes --> can lead to a response of .../...
ca2+; ca2+; exocytosis; receptor proteins; excitation; inhibition
119
(ch 37) acetylcholine excites ... but inhibits ...
skeletal muscle; cardiac muscle
120
(ch 37) dopamine is involved in ..., ..., and ...
emotions; learning; attention
121
(ch 37) serotonin is involved in ..., ..., ..., and ...
thermoregulation; sleeping; emotions; perception
122
(ch 37) endorphins bind to natural opiod receptors and contribute to a feeling of .... --> produced as response to ...
tranquility; stress
123
(ch 37) after a neurotransmitter has been released into the synaptic cleft and initiated a response, it is either;
.... by enzymes in postsynaptic membrane
... by presynaptic cell for .../....
this prevents continus .../... of postsynaptic membranes
inactivated; reabsorbed; repackagin; molecular membranes
124
(ch 37) inhibitory signals ... excitatory signals
cancel out
125
(ch 37) if a neuron receives many excitatory signals (either from synapse at rapid rate/ from different synapses) axon will likely
transmit nerve impulse
126
(ch 37) when excitatory neurotransmitter binds to a receptor, ... diffuses into postsynaptic neuron and action potential begins
Na+
127
(ch 37) hydrogen ions in low concentration on one side of membrane (chloroplasts & mitoc) and are dpumped to other side with addition of energy. establishes a larger electrochemical gradient across membrane and potential energy of this gradient can be used to do work, becoming KE for ATP production.
H+ can move back across membrane by interacting with
atp synthases
128
(ch 37) atp synthases have ... that allow H+ to flow .... , providing ... for ATP syntahse enzyme to produce ATP from ADP and phosphate (chemiosmosis)
atp production is tied to establishment of an ...
movement of h+ back across the membrane is ...
channels; down its electrochemical gradeitn; ke; H+ gradient; passive
