final exam Flashcards
(120 cards)
1
Q
A cell undergoes a series of divisions such that its daughter cells are 1/10 the radius of the parent cell. In these daughter cells, the surface/area volume has
A. Decreased by 10 X
B. Increased by 10 X
C. Decreased by 10^2 X
D. Increased by 10^2 X
E. Decreased by 10^3 X
A
b
2
Q
The term “allometry” refers to
a the limitation imposed by the time of diffusion
b the ability of cells to undergo biological changes to speed up diffusion
c the ability of an enzyme to speed up a given reaction
d the growth of body parts at different rates, resulting in a change of body proportions
e the measurement of osmotic pressures under different temperature conditions
A
d
3
Q
As the radius of a particle increases, the time it takes to diffuse a certain distance
goes up as the square of the radius goes down as the square of the radius goes up as the cube of the radius goes down as the cube of the radius goes up linearly with the radius of the particle
A
e
4
Q
As the radius of a particle increases, the diffusion coefficient for that particle
goes up as the square of the radius goes down as the square of the radius goes up as the cube of the radius goes down as the cube of the radius goes down linearly with the radius of the particle
A
e
5
Q
Glucose, which has a diffusion coefficient of about 5 * 10^-6 cm2/sec in a watery medium, moves about 1 micron in about 1 msec. How long would it take for glucose to move the length of a typical mammalian cell body, which is about 10 microns?
A. 10 msec
B. 100 msec
C. 1000 msec
D. 10,000 msec
E. 100 sec
A
b
6
Q
Hemoglobin has a diffusion coefficient that is approximately 10 times that of glucose. How long would it take for a single molecule of hemoglobin to move the length of a typical mammalian cell body, which is about 10 microns?
10 msec 100 msec 1000 msec 10,000 msec 100 sec
A
a
7
Q
The microvilli present on the epithelial cells of the small intestine are thought to
a Decrease the amount of time for molecules to diffuse across a membrane
b Significantly increase the surface area/volume ratio of a cell
c Decrease the diffusion coefficient for molecules diffusing across a cell membrane
d Increase the total amount of molecules that flow across the cells membrane each second
B&D
A
e
8
Q
Catalase is an enzyme that breaks down H2O2 into H20. Each catalase molecule can maximally convert 10^6 molecules of H2O2 to H20 per second. Imagine that there are 1000 molecules of catalase in a peroxisome, the organelle where it is normally located. What would be the Vmax for breakdown of H2O2 in this situation?
A. 10^6 molecules/sec
B. 10^7 molecules/sec
C. 10^8 molecules/sec
D. 10^9 molecules/sec
E. 10^12 molecules/sec
A
d
9
Q
Researchers examine the characteristics of catalase using 1 uM of the enzyme in their test tubes and discover in their experiments that in a solution mimicking the normal cytosol of a cell at a pH of 7.0, the Km is found to be 2.5 * 10-4 M. If the researchers then increase the concentration of catalase to 100 uM, the value for Km is likely to be
A. 2.5*10-4M
B. (2.5*10-4)2 M
C. 25*10-4M
D. 250 * 10-4M
E. 2.5*10-2M
A
a
10
Q
The “V” in the Michaelis-Menton equation is
A. the maximum velocity that can be achieved
B. the concentration at which 1⁄2 maximal velocity can be achieved
C. the rate at which a given product is formed at a given concentration of substrate
D. the minimum rate at which a product can be detected
E. the rate at which an individual enzyme can form a product ?
A
c
11
Q
An investigator is examining the properties of the enzyme carbonic anhydrase, and prepares a Lineweaver-Burke plot from the experiments she performed examining the rate of production of HCO3 when different concentrations of CO2 are added to a number of test tubes. She finds that the data can be fit by a straight line, and that the line, if extended from the data points, would cross the X axis at a value reading 0.1. This reading would mean that
A. The Vmax for the reaction is 1
B. The Vmax for the reaction is 0.1
C. The Vmax for the reaction is 10
D. The Km for the reaction is 0.1
E. The Km for the reaction is 10.
A
e
12
Q
The investigator above notes that the line also happens to cross the Y axis at a value of 0.1 This would indicate that
A. The Vmax for the reaction is 1 The Vmax for the reaction is 0.1 The Vmax for the reaction is 10 The Km for the reaction is 0.1 The Km for the reaction is 10.
A
c
13
Q
The investigator does a control series of experiments examining the production of HCO3 when different concentrations of CO2 are added to a number of test tubes lacking the enzyme. What should the investigator expect the graph of the data to look like when plotted as typical Michaelis-Menton plots are drawn?
A. A hyperbolic curve with a Vmax near 10 ?
B. A flat line
C. A straight line with a positive slope
D. A straight line with a negative slope
E. A hyperbolic curve that has no Vmax
A
b
14
Q
The enzyme phosphofructokinase plays an important role in the glycolytic pathway, converting fructose 6 phosphate to fructose 1,6 bisphosphate. Stimulation of this pathway leads to the production of pyruvic acid, which ultimately produces high levels of ATP. ATP can bind to the enzyme phosphofructokinase and slow down its activity. This type of regulation is likely to result in
A. an increase in Vmax
B. a decrease in Km
C. a decrease in Vmax and Km
D. a decrease in Vmax
E. Vmax and Km are likely to remain the same
A
d
15
Q
The effects of the binding of ATP onto the enzyme phosphofructokinase could be referred to as
A. feedback inhibition
B. competitive inhibition
C. allosteric regulation
D. enzyme denaturation
E. A&C
A
a
16
Q
AMP (adenosine mono phosphate) can bind to the enzyme phosphofructokinase and significantly increase the amount of fructose 1,6 bisphosphate that is produced. This type of regulation is likely to result in
A. an increase in Vmax
B. a decrease in Km ?
C. a decrease in Vmax and Km
D. a decrease in Vmax
E. Vmax and Km are likely to remain the same
A
a
17
Q
An investigator is examining the pressures associated with osmosis. She adds 30 millimoles of MgCl2 to water, bringing the volume of water up to 100 ml (milliliters). The solution is at normal room temperature. The investigator would now have a solution with what level of osmolarity?
A. 30 mosm
B. 60 mosm
C. 90 mosm
D. 300 mosm
E. 900 mosm
A
c
18
Q
The investigator now heats the solution to 75oC. What will happen to the osmotic pressure associated with this solution?
A. it stays the same
B. it increases linearly with the rise in temperature
C. it decreases linearly with the rise in temperature
D. it increases as the square of the rise in temperature
E. it decreases as the square of the rise in temperature
A
b
19
Q
The plasma osmolarity of a skipjack tuna is close to 400 mosm. The ocean water the fish is swimming in is estimated to be about 1 osmolar. The osmotic pressure difference is likely to be close to
A. 1atm
B. 5atm
C. 10 atm
D. 24 atm
E. 48 atm
A
c
20
Q
For the skipjack tuna, a significant physiological problem that it needs to solve is
A. excess water flowing into its blood
B. water flowing out of its body into the water it is swimming in
C. excess salt flow into its blood
D. salt flow out of its blood into the water it is swimming in
E. B&C
A
e
21
Q
A hammerhead shark is now chasing the skipjack tuna, hoping to have it for dinner. What major physiological problem does the hammerhead shark face as it devours its prey?
A. excess water flowing into its blood
B. water flowing out of its body into the water it is swimming in
C. excess salt flow into its blood
D. salt flow out of its blood into the water it is swimming in
E. B&C
A
c
22
Q
The hammerhead shark is not satisfied after eating the skipjack tuna and spots a stingray gliding close to the ocean floor. It now devours the stingray, and notices that this meal tastes quite a bit different than when it ate the tuna. In what way would the blood of the stingray be expected to differ from the skipjack tuna?
A. It would have high levels of urea
B. it would have high levels of TMAO (trimethylamine oxide)
C. it would have higher levels of chloride
D. It would have high levels of all of the above
E. it would actually not be very different from the tuna.
A
d
23
Q
The transporter associated with the movement of vitamins across the cell membrane in the basolateral membrane of epithelial cells of the proximal tubule
A. Moves both Na and vitamins against their concentration gradient
B. Moves Na against its concentration gradient but vitamins moves with its concentration gradient
C. Pumps vitamins against its concentration gradient but Na moves with its concentration gradient
D. Pumps both Na and vitamins down along their concentration gradient
E. Does not use Na when transporting vitamins
A
e
24
Q
Which animal would be expected to have particularly short loops of Henle?
A. Rattlesnake
B. Frog
C. Giraffe
D. Desert rat
E. lion
A
b
25
High levels of antidiuretic hormone (ADH) in the blood
A. result in water leaving the lumen of the collecting duct and entering the extracellular fluids
B. results in an increase in the movement of salt from the extracellular fluids to the lumen of the collecting duct
C. increases the permeability of cells in the collecting duct to water
D. results in increases in the activity of the Na/K ATPase in the epithelial cells of the collecting duct
E. A&C
e
26
Stimulation of an epithelial cell in the collecting duct by antidiuretic hormone (ADH)
A. promotes the fusion of vesicles in the cytoplasm to the plasma membrane of epithelial cells
of the collecting duct
B. reduces the number of aquaporins in the plasma membrane of these cells
C. reduces the amount of cAMP in the cell
D. turns off the activity of a G protein in the cells
E. results in the insertion of glucose transporters into the plasma membrane
a
27
The reabsorption of sodium occurs in which part of the nephron?
A. glomerulus
B. ascending limb of the loop of Henle ?
C. proximal tubule
D. descending limb of the loop of Henle
E. B&C
e
28
A competitive inhibitor of antidiuretic hormone (ADH) would result in which of the following if an individual had been drinking plenty of water for the past several days?
A. More salt leaving the urine than normal
B. Less salt leaving the urine than normal
C. A significantly higher permeability of the collecting duct to water
D. A significantly lower permeability of the collecting duct to water
E. Not much of a change to either salt or water excretion
e
29
A non-competitive inhibitor of cAMP or protein kinase C (PKC) would result in which of the following if an individual had been walking in the dessert with little water for the past several days?
A. More total salt leaving the urine than normal
B. Less total salt leaving the urine than normal
C. A significantly higher permeability of the collecting duct to water
D. A significantly lower permeability of the collecting duct to water
E. Not much of a change to either salt or water excretion
d
30
he cell of a goldfish muscle is placed in a solution mimicking the blood plasma of the fish. In this case, the solution surrounding the cell could be considered to be ________ compared to the solution on the inside of the cell.
A. hypotonic
B. hypertonic
C. isotonic
D. hydrophobic
E. Hyperphobic
c
31
Which of the following is found in the apical membrane of a cell from a serous acinar salivary gland epithelial cell?
A. Na/K ATPase
B. K+ channel
C. carbonic anhydrase
D. protein kinase C
E. Cl- channel
e
32
Amylase acts to
A. break down proteins into mono- and di-peptides
B. increase the activity of protein kinase C
C. release calcium from intracellular organelles
D. break down starch
E. increase levels of cAMP
d
33
Thapsigargin is a pharmaceutical agent that will eliminate the release of calcium from the endoplasmic reticulum. When added to salivary gland epithelial cells stimulated by acetylcholine and noradrenaline, it will likely result in
A. a decrease in the amount of amylase released
B. an inability to increase the insertion of chloride channels into the plasma membrane
C. an inability to increase water accumulation into the lumen
D. an inability to increase sodium accumulation into the lumen
E. B,C&D
c
34
The basolateral membrane of the epithelial cells of the small intestine are likely to
A. have high levels of Na/K ATPase
B. have high levels of Na-coupled transporters
C. have high levels of Na-coupled amino acid transporters
D. have close associations with blood capillaries
E. A&D
e
35
The G-protein associated with noradrenaline activation of epithelial cells of the salivary gland most directly
A. activates adenylate cyclase
B. increases cAMP levels
C. increases protein kinase A activation
D. results in the insertion of chloride channels into the plasma membrane
E. leads to the insertion of aquaporins into the cell membrane
a
36
The effects of acetylcholine on potassium channel permeability in the salivary gland could best be described as
A. an increase in Vmax
B. an increase in Km
C. a decrease in Vmax
D. a decrease in Km
E. an increase in Vmax and a decrease in Km
a
37
The regulatory effects of thyroid hormones on Na/K ATPase activity in many cells can best be described as
A. an increase in Vmax
B. an increase in Km
C. a decrease in Vmax
D. a decrease in Km
E. an increase in Vmax and a decrease in Km
a
38
he regulatory effects of Aldosterone on Na/K ATPase activity in many cells can best be described as
A. an increase in Vmax
B. an increase in Km
C. a decrease in Vmax
D. a decrease in Km
E. an increase in Vmax and a decrease in Km
a
39
ATP-driven calcium pumps can be found in
A. the plasma membrane of many cells
B. mitochondria
C. endoplasmic reticulum
D. all of the above
E. none of the above
d
40
Channel proteins that will selectively allow calcium to move from high to low concentrations can be found in
A. the plasma membrane of many cells
B. mitochondria
C. endoplasmic reticulum
D. all of the above
E. none of the above
d
41
The ratio of outside calcium concentration to inside calcium concentration in many cells is approximately
A. 10
B. 0.1
C. 100
D. 0.01
E. 1000
d
42
The resting membrane potential of many cells in the body is due most immediately and directly to
A. primary active transport
B. secondary active transport
C. carrier mediated transport
D. facilitated transport through channel proteins
E. diffusion directly across the lipid membrane of cells
a
43
A researcher examines the voltage across the inside of a neuron from a fish previously unknown to science. She places one electrode inside the cell and has a second electrode in the extracellular solution. She sets the extracellular potassium concentration equal to 1 mM. She measures a transmembrane potential of -60 mV at room temperature. What is the likely concentration of potassium on the inside of this cell?
A. 0.1 mM
B. 1mM
C. 10mM
D. 100 mM
E. 1000 mM
c
44
The researcher then evokes an action potential in this strange neuron. She sets the extracellular sodium concentration to 100 mM. At the peak of the action potential, the researcher records a transmembrane voltage of 0 mV. What is the likely concentration of sodium on the inside of the cell?
A. 0.1 mM
B. 1mM
C. 10mM
D. 100 mM
E. 1000 mM
d
45
There are two solutions adjacent to one another in a beaker. Compartment A contains 100 mM NaCl. Compartment B has 10 mM NaCl. An experimenter defines side A as being at ground potential (that is, 0 V). Under these conditions, the calculated value for the Nernst equilibrium potential for sodium would be __ and the Nernst equilibrium potential for chloride would be ___
A. ENa=+60mV,ECl=-60mV
B. ENa=-60mV,ECl=+60mV
C. ENa=+60mV,ECl=+60mV
D. ENa=-60mV,ECl=-60mV
E. 0, 0
b
46
An investigator changes extracellular and intracellular chloride levels so that the outside concentration is 1 mM and the inside concentration is 100 mM. If chloride channels were forced to open up in this condition, they would drive the cell to what voltage value?
A. +120 mV
B. +60 mV
C. 0mV
D. -60mV
E. -120 mV
E
47
A nerve cell is associated with the following parameters:
PNa=100 Naout =100mM Nain =1mM
PCl=1mM PClout= 100mM PClin =1mM
PK=100 Kin =100mM Kout =1mM
What is the voltage of a cell that has these values close to?
-120 mV
-60 mV
0mV
+60 mV
+120 mV
0mv
48
A diseased cell has an intracellular calcium concentration of 0.1 mM. The extracellular solution has a normal amount of calcium. The mitochondria has its normal level of internal
calcium. If many calcium channels were opened in a mitochondria were opened up, what would the voltage of the interior of the mitochondria likely be compared to the cytoplasm of the cell?
A. –90mV
B. -60mV
C. -30mV
D. 0 mV
E. +60mV
b
49
. In the same diseased cell, if many calcium channels opened in the plasma membrane of the cell, what would the transmembrane voltage across the plasma membrane be?
A. –60mV
B. -30mV
C. +30mV
D. 0 mV
E. +60mV
a
50
During the relative refractory period,
A. voltage-gated potassium channels are open in large numbers
B. sodium channels are closed and unable to open even if the cell is depolarized
C. voltage-sensitive potassium channels are locked shut
D. sodium channels are open most fully
E. the voltage of the cell is just beneath the threshold voltage needed to initiate an action potential.
a
51
Why might the resting membrane potential of a cell slightly more depolarized than the value for the Nernst equilibrium potential for potassium?
A. A small fraction of the leak channels are closed
B. Voltage-activated calcium channels are open
C. The leak channels allow a small amount of sodium to enter the cell
D. The resting membrane potential is never more depolarized than the value for the Nernst equilibrium potential for potassium
E. Chloride channels are open
c
52
What effect does decreasing the extracellular potassium have on the resting membrane potential?
A. The resting membrane potential will disappear.
B. The resting membrane potential becomes more negative
C. The resting membrane potential will not change
D. The resting membrane potential will become less negative.
E. The resting potential is first more negative, then more positive
d
53
A nerve cell is associated with the following parameters:
PK=100 PNa= 1 PCl = 100
Ko=10mM Ki=100 Nao=100 Nai=1 Clo= 100 Cli = 10
What is the voltage of a cell that has these values close to?
A. -120 mV
B. -60 mV
C. 0 mV
D. +60 mV
E. +120 mV
b
54
What effect does decreasing the extracellular calcium concentration have on the resting membrane potential?
A. The resting membrane potential will disappear.
B. The resting membrane potential becomes more negative
C. The resting membrane potential will not change
D. The resting membrane potential will become less negative.
E. The resting potential is first more negative, then more positive
c
55
An investigator introduces a significant number of light-sensitive potassium channels into a nerve cell. These channels have the same permeability characteristics as the leak channels. Before light is put on, the cell has a resting potential of -55 mV. What will the voltage of the cell likely be when the cell is illuminated by light?
A. -120 mV
B. -70 mV
C. -55mV
D. 0 mV
E. +60 mV
b
56
The voltage across the cell membrane at which an action potential can be elicited from a neuron is called the
A. overshoot
B. resting potential
C. undershoot
D. threshold
E. tonic response
d
57
Local depolarizations of nerve cells that lead to the formation of an action potential are generally generated at
A. The dendrites of the cell
B. The axon hillock
C. the axon itself
D. the synaptic terminal
E. all of the above
a
58
Glial cells that wrap axons act electrically as
A. conductors
B. capacitors
C. current injectors
D. amplifiers
E. insulators
e
59
A nerve cell which normally rests at -60 mV is impaled with an electrode and the transmembrane voltage is held constant by this electrode at - 45 mV. During this time,
A. potassium will flow into the cell
B. potassium will flow out of the cell
C. sodium will flow out of the cell
D. potassium and sodium will flow out of the cell
E. none of the above
b
60
The inactivation gate of sodium channels
A. is voltage-independent
B. is activated by hyperpolarization
C. is activated by depolarization
D. is activated only when the cell reaches the peak of the action potential
E. is activated only when the voltage of the cell has dropped below threshold for activation
d
61
The neurotransmitter acetylcholine interacts with a G-protein-coupled receptor present in heart cells. Activation of this G-protein
A. causes calcium channels to open and heart cells to become depolarized
B. causes calcium channels to close and heart cells to produce more frequent action potentials
C. activates potassium channels and makes action potentials less frequent
D. activates potassium channels and produces more frequent action potentials ?
E. opens calcium channels and causes oscillations in the voltage of the heart cells
c
62
The neurotransmitter GABA could cause inhibition of a nerve cell by
A. binding to a receptor protein, causing it to open and allow the influx of chloride
B. binding to a receptor protein, causing it to open and allow the efflux of potassium
C. binding to a receptor coupled to a G-protein, causing a separate calcium channel to open
D. binding to a receptor coupled to a G-protein, causing a separate chloride channel to open
E. A,B&D
e
63
Vesicles in the nerve cells which use glutamate as a neurotransmitter typically possess
A. a Na/K ATPase
B. a sodium/potassium coupled glutamate transporter
C. a proton-glutamate co-transport protein
D. an ATP-driven proton pump
E. all of the above
d
64
Lithium is a compound that is often used to replace extracellular sodium, but generally cannot be used by sodium-dependent transporters and ATPases in cells. If all extracellular sodium surrounding a nerve cell were replaced by lithium, what would happen over a prolonged period of time?
A. Intracellular sodium levels would likely increase
B. transport of the neurotransmitter glutamate from the extracellular space to the cytoplasm would likely decrease
C. transport of glutamate into the interior of synaptic vesicles would increase
D. transport of protons into the interior of synaptic vesicles would decrease
E. B,C&D ?
b
65
The molecule in a vertebrate rod photoreceptor that actually catches a photon of light is called
A. iodopsin
B. opsin
C. 11-cis retinal
D. transducin
E. cGMP
c
66
In a vertebrate rod photoreceptor, opsin directly interacts with
A. transducin
B. 11-cis retinal
C. PDE (phosphodiesterase)
D. cGMP
E. A&B
e
67
Vertebrate photoreceptors are similar to olfactory cells in that
A. They both produce hyperpolarizations to stimuli
B. They both have cyclic nucleotide channels as part of their signal transduction pathway C. They both use G-proteins as part of their signal transduction pathway
D. They both degrade cGMP to produce a change in voltage
E. B&C
e
68
Which photoreceptors are most important in color perception?
A. Rods
B. Cones
C. Rods and Cones
D. Retinal pigment epithelial cells
E. None of the above
b
69
In olfactory cells, the molecule adenylate cyclase
A. Binds to an odorant
B. Activates a G protein
C. produces cAMP
D. directly interacts with an ion channel to allow the influx of sodium
E. directly interacts with an ion channel to decrease the flow of sodium into a cell
c
70
the alpha (α) subunit of a G-protein in the cilia of olfactory neurons
A. binds to an odorant
B. produces cAMP
C. stimulates adenylate cyclase
D. acts to directly open ion channels
E. acts to directly close ion channels
c
71
You leave a movie theater at noon and head to the lake to take in a game of volleyball. What will happen to your visual perception?
A. You will become more sensitive to light
B. You will become less sensitive to light
C. Your sensitivity to incoming light will not change
D. Your retinal epithelial cells will become sensitive to light
E. Your sensitivity to light will first decrease and then increase
B
72
The sensation of “bitterness” can result from
A. A block of potassium channels in taste buds by protons
B. The flow of sodium across a sodium-selective channel
C. the closure of chloride channels in taste buds via a G-protein signal transduction pathway
D. the production of IP3 via a G-protein-coupled signal transduction pathway with subsequent increases in intracellular calcium
E. A & D
e
73
Channels sensitive to mechanical stimulation in hair cells are thought to be located in the
A. dendrites
B. axons
C. axon terminals
D. stereocilia
E. support cells
d
74
Vibrations in the air will most directly
A. cause mechanical movement of the tympanum
B. cause mechanical movement of the incus
C. cause mechanical movement of the basilar membrane
D. cause mechanical movement in the stereocilia
E. cause mechanical movement in the kinocilia
a
75
In hearing, low frequency sounds are transduced
A. by hair cells near the oval window
B. by hair cells near the round window
C. by hair cells at the apex (far end) of the cochlea
D. by hair cells throughout the distance along the basilar membrane
E. A&B
c
76
Sharks, skates and sting-rays differ from many other fish swimming in the ocean in that
A. They are much more sensitive to mechanical stimulation (water movements) than other ocean fish
B. They have much higher sensitivities to olfactory cues than other ocean fish
C. They are able to sense the weak electric fields created by other organisms in the water
D. They are much more sensitive to light than other ocean fish.
E. They can hear at much higher frequencies than other fish.
c
77
A G-protein coupled signal transduction system has the advantage of
A. Being able to send signals over large distances
B. A response that does not decay significantly with time
C. Direct coupling with vesicular fusion and neurotransmitter release
D. Very high degrees of amplification of the original signal
E. Rapid frequency response
d
78
A fish is swimming in Lake Michigan in autumn, while a second fish is swimming in warm tropical seas around the equator. Which statement is true?
A. The fish swimming in Lake Michigan will have a more challenging task in acquiring needed oxygen.
B. The fish swimming in Lake Michigan will have an easier task in acquiring needed oxygen.
C. The fish swimming in Lake Michigan is likely to get its oxygen directly from the air.
D. The fish swimming in Lake Michigan will have an easier task getting rid of carbon dioxide building up in its blood
E. The fish swimming in Lake Michigan will have a harder task in getting rid of carbon dioxide.
b
79
The diffusion coefficient for oxygen in air compared to water is about
A. 10^6 times lower
B. 10^6 times larger
C. 100 times lower
D. 100 times larger
E. they are about the same
b
80
A decrease in acidity of your blood will
A. Increase the value for the P50 for blood oxygenation
B. Decrease the value for the P50 for blood oxygenation
C. shift the blood oxygenation curve upward
D. shift the blood oxygenation curve downward
E. will not likely have an effect on the blood oxygenation curve
b
81
2,3 DPG (diphosphoglycerate) is an important compound because
A. it increases the ability of hemoglobin to bind to oxygen
B. it induces the production of the alpha (α) subunit of hemoglobin
C. it increases the P50 value of the blood oxygenation curve
D. it speeds the flow of blood through the alveolar capillaries
E. it increases the Hill coefficient (n), steepening the blood oxygenation curve
c
82
Increasing the thickness of a respiratory membrane from 1 to 10 microns would
A. increase the flux of a gas across that membrane by 10 X
B. increase the flux of a gas across that membrane by 10^2 X
C. increase the flux of a gas across that membrane by 2^10
D. increase the time it takes for gas to get across the membrane by 10X
E. increase the time it takes for a gas to get across the membrane by 10^2
D
83
The thickness of the respiratory membrane of your lungs is typically about
A. 0.5 um
B. 10um
C. 100 square meters
D. 1 square meter
E. 347 square microns
a
84
One reason that pneumonia can be so devastating is that
A. it increases the effective area of the respiratory membrane
B. it decreases the effective difference in the partial pressure of oxygen across the respiratory membrane
C. it increases the time it takes for a gas to diffuse across the respiratory membrane
D. it decreases the diffusion constant for oxygen
E. it decreases the time it takes for blood to flow through the capillaries surrounding the alveoli
c
85
As you sit in this room taking this exam, the partial pressure for oxygen in your pulmonary arteries is about ____ mm Hg and the partial pressure for carbon dioxide is about ____ mm Hg
A. 40; 46
B. 100; 40
C. 100; 46
D. 40; 40
E. 160; 46
B
86
How many red blood cells do you typically have in your blood as you sit here taking this exam?
A. 1X10^6
B. 250 X 10^6
C. 5X10^6
D. 400,000
E. 2.5 X 10^13
e
87
Myoglobin differs from hemoglobin in that
A. it has a higher affinity for oxygen
B. it has a steeper S-shaped curve
C. it can hold more oxygen per molecule
D. it is made of only two subunits
E. all of the above
a
88
Looking at the Hill equation, the parameter that defines the steepness of the curve is
A. the value for P50
B. the value for Rmax
C. the value for R
D. the value for n
E. the value for Km
d
89
When CO2 binds to hemoglobin,
A. it displaces oxygen from its binding site
B. it decreases the value for P50
C. it steepens the S-shape of the oxygen binding curve
D. it decreases the affinity of hemoglobin for oxygen
E. it decreases the release of oxygen from hemoglobin
d
90
A fetus predominately expressing the α and β subunits for hemoglobin
A. would be perfectly healthy
B. would have a hard time getting enough oxygen from the mother’s blood
C. would have a blood oxygenation curve shifted to the left compared to the mother’s blood
D. would have a blood oxygenation curve that lacks an S-shape
E. would have a P50 shifted to the right compared to the mother’s blood
b
91
For a fish swimming and feeding just beneath the surface of the water in the Sargasso Sea off the coast of Bermuda on a warm, hot sunny day, the partial pressure for oxygen entering its gills would be close to
A. 760mmHg
B. 160mmHg
C. 100mmHg
D. 45 mm Hg
E. 40mmHg
b
92
A second fish is swimming and feeding just beneath the surface of the water in the Arctic Ocean on a cold, cloudy day. For this fish, the partial pressure for oxygen entering its gills would be close to
A. 760mmHg
B. 160mmHg
C. 100mmHg
D. 45 mm Hg
E. 40mmHg
b
93
Which fish would be drawing in water with more oxygen dissolved in it?
A. a fish swimming in the Sargasso Sea on a warm, hot sunny day
B. a fish swimming in the Arctic Ocean on a cold, cloudy day
C. a fish swimming in warm water near the equator
D. a fish swimming in lake Michigan on a hot sunny day in the summer
E. a fish swimming in Lake Michigan on a cold, winter day with the water just above freezing temperatures
e
94
A goldfish has been born with an aberrant respiratory system – the blood flow through the gill lamella now runs in the same direction as the water that is passing through the lamella. As it swims close to the surface of the water at Lake Michigan, what will the likely partial pressure values for oxygen in the water and blood at the very end of the gill lamellae?
O2 in water : O2 in blood
A. 160: 150
B. 0.5: 160
C. 80: 80
D. 20:10
E. 160:10
c
95
A happy little normal goldfish is swimming near the top of the water in Lake Michigan. Blood is flowing normally through the gill lamellae. What would be reasonable values for the partial pressure of oxygen (in mm Hg) in the water and in the blood at the very end of the gill lamellae when the water is just leaving the gill?
O2 in water : O2 in blood
A. 160:150
B. 20: 10
C. 80:80
D. 10:150
E. 150:160
b
96
As blood from the heart makes its way around an alveolus, which of the following occurs?
A. Chloride flows into red blood cells
B. CO2 combines with H+ to form H2CO3
C. HCO3 flows into red blood cells
D. albumin binds to H+
E. CO2 binds to hemoglobin
c
97
As blood from the heart goes through the capillaries surrounding a muscle cell, carbonic
anhydrase plays a critical role in speeding up the formation of
A. H+
B. CO2
C. carbaminohemoglobin
D. HCO3
E. A&D
e
98
When plotted with pH on the Y axis and levels of acid or base on the X axis, what would happen to the buffering curve of a chemical buffer if the pK for the buffer were to suddenly increase by 1 unit?
A. It would shift upwards
B. It would shift downwards
C. It would flatten out
D. It would become steeper
E. It would shift to the right
a
99
A buffer has a pK of 2 and the pH of the solution is 7. Which statement would be correct?
A. Most of the buffer has a proton (H+) attached to it
B. Most of the buffer does not have a proton (H+) attached to it
C. Half of the buffer will have a proton (H+) on it, and half will not
D. The titration curve for the buffer will no longer have an S-shape
E. All of the buffer will have a proton attached to it
b
100
As blood moves from the beginning of a capillary in a muscle to the end and exists the muscle, the CO2 equilibrium curve
A. shifts to the right
B. shifts to the left
C. does not change
D. shifts downward
E. shifts upward
a
101
A person has a disease which results in him producing twice the amount of HCO3 that a normal individual produces. If this person has PCO2 levels that are identical to normal
values, the pH of this person’s blood would be likely to be closest to
A. 7.7
B. 7.4
C 7.0
D. 6.1
E. 5.0
a
102
A person has a genetic abnormality that results in an increased respiratory drive to exhale CO2. If CO2 levels for this individual were to be 1⁄2 the normal levels, and levels of HCO3 were maintained at normal levels, this person’s blood would likely have a pH close to
A. 7.7
B. 7.4
C 7.0
D. 6.1
E. 5.0
a
103
If an individual had equal levels of CO2 and HCO3 in their blood, the blood pH would be close to
A. 7.7
B. 7.4
C 7.0
D. 6.1
E. 5.0
d
104
A beaker of water is cooled from 25oC to 15oC. Which statement about the solution is correct?
A. the pH will decrease and the concentration of OH- will decrease
B. the pH will increase and the concentration of OH- will increase
C. the pH will increase and the concentration of OH- ions will decrease
D. the pH will decrease and the concentration of OH- will increase
E. The pH and OH- concentrations will not change significantly
c
105
Which animal is likely to maintain the highest partial pressure difference for oxygen as blood courses through the capillaries of the respiratory membrane?
A. tiger salamander
B. tiger
C. snake
D. swan
E. ant
a
106
I am challenged to swim as far as possible under the water in a pool that is 100 years long. To prepare for this, I hyperventilate (breathe hard in and out), increasing my ventilation rate to 20 liters per minute. This would likely result in
A. A large increase in the amount of hemoglobin having an oxygen molecule on it
B. A large increase in the amount of bicarbonate in the blood
C. A significant alkalinization of my blood
D. A shift in the blood oxygenation curve for hemoglobin to the right
E. B&D
c
107
An increase in levels of carbaminohemoglobin in a red blood cell would likely be associated with
A. increases in hemoglobin molecules with H+ attached
B. decreases in the levels of chloride in a cell
C. decreases in the number of molecules of albumin with a H+ attached
D. increases in the pH of the blood plasma
E. decreases in the levels of carbonic anhydrase in a cell
a
108
In vertebrate muscles, tetanus results from
A. the addition of voltage changes in the muscle, leading to a larger overall depolarization
B. inhibition of muscle fibers induced by the influx of chloride
C. multiple rapid action potentials in the muscle that result in the addition of tensions
produced by each twitch
D. increased numbers of calcium channels opening in the muscle plasma membrane
E. the lack of a sufficient amount of ATP in the muscles.
c
109
The ryanodyne receptor plays an important role in
A. acting as a calcium buffer in the sarcoplasmic reticulum
B. preventing actin and myosin from interacting
C. pumping calcium into the interior of the sarcoplasmic reticulum
D. regulating calcium release from the sarcoplasmic reticulum
E. preventing tetanus in skeletal muscle fibers
d
110
Which of the following is/are FALSE about Purkinje fibers in the heart:
A. they are considered to be conduction fibers.
B. transmission through the purkinje fibers is very fast
C. they do not have pacemaker ability.
D. they are connected to the branches of the bundle of His.
E. all of the above
c
111
Which of the following is/are TRUE about diastole (at rest)?
A. Diastole accounts for 93.5% of the cardiac cycle
B. Diastole accounts for 65% of the cardiac cycle
C. Diastole accounts for 50% of the cardiac cycle
D. Diastole accounts for 45% of the cardiac cycle
E. Diastole accounts for 35% of the cardiac cycle
b
112
In a lab setting, a nerve-muscle preparation is prepared that has a motorneuron connected to a muscle. Two electrodes are placed in the muscle, one to record changes in voltage, the other to allow direct electrical stimulation of the muscle. A thin wire electrode is threaded through the muscle, allowing the entire cell to be stimulated. Tetrodotoxin, which binds to and blocks voltage-aged sodium channels, is added in sufficient amounts to block all those channels. What will happen?
A. Electrical stimulation of the motorneuron could still produce a contraction of the muscle but no action potential
B. Electrical stimulation of the muscle directly could still produce a contraction but no action potential
C. Electrical stimulation of the muscle directly could still produce a contraction and an action potential in the muscle.
D. Electrical stimulation of both the motorneuron and the muscle together would be necessary to generate a contraction
E. Electrical stimulation in either cell could not resut in a contraction of the muscle cell.
c
113
What statement is correct about sacromeres less than 1.2 um in length and greater than 3.6 um in length?
A. tetanus can occur in the longer ones but on in the shorter ones
B. the latent period will be longer in the longer ones but shorter in the shorter ones.
C. Neither can produce a significant amount of tension.
D. Both are capable of tetanus if action potential frequency is increased sufficiently
E. Both produce significantly more tension when activated than a sarcomere that is 2.5 um in
Length.
c
114
There is an accident in Thom Park’s lab when he is examining the effects of CO2 on naked mole rat behavior. Suddenly, the amount of CO2 in the room increases to 20% of the total amount of gas, although the total air pressure in the room remains at 1 atm. As the blood pass around each alveolus in the lung, what will happen?
A. Chloride will move out of red blood cells
B. Levels of bicarbonate will increase
C. Amounts of acid bound to hemoglobin will decrease
D. Concentrations of albumin will decrease
E. None of the above
e
115
Changing the partial pressure of oxygen in a room in which you are breathing from 160 mm Hg to 100 mm Hg
A. increase your alveolar ventilation rate significantly
B. decrease the level of acidity in the blood
C. increase the level of acidity of the blood
D. alter the sensitivity of hemoglobin to H+
E. none of the above
e
116
The binding of ATP to myosin most immediately leads to
A. release of calcium from intracellular stores
B. contraction of a muscle fiber
C. separation of the head group of myosin from actin
D. the uptake of calcium into the sarcoplasmic reticulum
E. attachment to troponin
c
117
Troponin binds to
A. calcium
B. myosin
C. actin
D. ATP
E. A&C
28. The A ban
E
118
The A band of muscle consists of
A. actin
B. myosin
C. calsequestin
D. just the myosin head groups
E. A&B
e
119
One difference between muscles of vertebrates and invertebrates is that
A. invertebrate muscle fibers can receive input from excitatory and inhibitory neurons
B. vertebrate muscles are activated by action potentials in the muscles, while in invertebrates,
graded electrical potentials can control contraction
C. vertebrate muscles use calcium to initiate contraction, while invertebrates use ATP
D. invertebrate muscle fibers do not have functional sarcomeres
E. A&B
e
120
In pacemaker potentials in cardiac muscle cells, what is the correct sequence of events that takes place following an action potential?
A. K+ channels close→ T-type Ca++ channels open→ L-type Ca++ channels open→ funny NA+
channels open
B. K+ channels close→ funny NA+ channels open→ T-type Ca++ channels open→ L-type Ca++
channels open
C. funny NA+ channels open→ L-type Ca++ channels open→ T-type Ca++ channels open→
K+ channels close
D. All of the above
E. None of the above
b
