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Test Bank xx
Multiple Choice xx
1. The subcellular structure that degrades proteins is called the:
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A. Tight junction xx
B. Mitochondria
C. Lysosome
D. Plasma membrane xx
E. Ribosome
ANS: C x x
2. An experiment is done to measure the uptake of an amino acid into a cell. The followi
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ng data are obtained:
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N
If Na+ is removed from the extracellular bathing solution, or if a drug is added that prevents t
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he cell from making adenosine triphosphate (ATP), the uptake of amino acid into the cell is
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xmarkedly reduced. According to this information, which of the followingmechanisms is pro
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bably responsible for the transport of the amino acid into the cell?
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A. Passive diffusion through the lipid bilayer xx xx xx xx xx
B. Uniporter
C. Transport ATPase xx
D. Na+ symporter xx
E. Na+ antiporter
xx
ANS: D
xx x x
3. A membrane permeable by only Na+ separates two compartments containin
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g Na2SO4,shown as follows:
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,Electrodes are placed in both compartments, and a voltage is applied (that of compartment A
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is held at 0 mV). What voltage applied to compartment B would resultin no net movement o
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f Na+ across the membrane separating the compartments?
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A. –60 mV xx
B. –30 mV xx
C. 0 mV
xx
D. +30 mV xx
E.
+60 mV xx
ANS: E
xx x x
4. The resting membrane potentN ial oRf a Ic e llGis –
USN
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B85.m
CV. The intracellular and extracellular concentrations of several ions are indicated
xx xx
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in the following table, as is the calculated
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Nernst equilibrium potential (Ei) for each of these ions:
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Ion Concentration Concentration Ei
Inside Cell xx Outside Cell xx
+
Na 12 mEq/L xx 145 mEq/L xx 66 mV
xx
K+ 150 mEq/L xx 4 mEq/L
xx –96 mV xx
Cl– 30 mEq/L xx 105 mEq/L xx –33 mV xx
Ca++ 0.0001 mmol/dL xx 1 mmol/dL
xx 122 mV xx
The membrane has channels for Na+, K+, Cl–
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, and Ca++. The conductance of the membrane is the greatest for which ion?
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A. Na+
B. K+
C. Cl–
D. Ca++ A x x
NS: B xx
5. A cell contains the following membrane transporters:
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Na+ channelK+ channel
xx xx
Na+,K+-ATPase
xx
, The resting membrane voltage of the cell is –80 mV, and the intracellular and
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