Test Bank for Berne & Levy Physiology 8th Edition by Bruce M. Koeppen

Test Bank For Berne & Levy Physiology, 8th Edition
Chapter 01: Principles of Cell Function


Chapter 01: Principles of Cell Function
MULTIPLE CHOICE

1. The subcellular structure that degrades proteins is called the:
a. Tight junction
b. Mitochondria
c. Lysosome
d. Plasma membrane
e. Ribosome

ANS: C

2. An experiment is done to measure the uptake of an amino acid into a cell. The
following data are obtained:




If Na+ is removed from the extracellular bathing solution, or if a drug is added that
prevents the cell from making adenosine triphosphate (ATP), the uptake of amino acid
into the cell is markedly reduced. According to this information, which of the following
mechanisms is probably responsible for the transport of the amino acid into the cell?
a. Passive diffusion through the lipid bilayer
b. Uniporter
c. Transport ATPase
d. Na+ symporter
e. Na+ antiporter

ANS: D




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,Test Bank For Berne & Levy Physiology, 8th Edition
Chapter 01: Principles of Cell Function

3. A membrane permeable by only Na+ separates two compartments containing Na2SO4,
shown as follows:




Electrodes are placed in both compartments, and a voltage is applied (that of
compartment A is held at 0 mV). What voltage applied to compartment B would result in
no net movement of Na+ across the membrane separating the compartments?
a. –60 mV
b. –30 mV
c. 0 mV
d. +30 mV
e. +60 mV

ANS: E

4. The resting membrane potential of a cell is –85 mV. The intracellular and extracellular
concentrations of several ions are indicated in the following table, as is the calculated
Nernst equilibrium potential (Ei) for each of these ions:
Ion Concentration Concentration Ei
Inside Cell Outside Cell
Na+ 12 mEq/L 145 mEq/L 66 mV
+
K 150 mEq/L 4 mEq/L –96 mV
Cl– 30 mEq/L 105 mEq/L –33 mV
++
Ca 0.0001 mmol/dL 1 mmol/dL 122 mV

The membrane has channels for Na+, K+, Cl–, and Ca++. The conductance of the
membrane is the greatest for which ion?
a. Na+
b. K+
c. Cl–
d. Ca++

ANS: B

5. A cell contains the following membrane transporters:
Na+ channel
K+ channel
Na+,K+-ATPase




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,Test Bank For Berne & Levy Physiology, 8th Edition
Chapter 01: Principles of Cell Function

The resting membrane voltage of the cell is –80 mV, and the intracellular and
extracellular ion concentrations are as follows:
Ion Intracellular Extracellular Concentration
Concentration
Na+ 10 mEq/L 145 mEq/L
+
K 120 mEq/L 4 mEq/L

The cell is treated with a drug to inhibit the Na+,K+-ATPase. What would be the effect of
this drug on the following parameters?

Intracellular [Na+] Intracellular [K+] Cell Volume Membrane Voltage
a. Decrease Decrease Decrease Depolarize
b. Increase Decrease Increase Depolarize
c. Increase Increase Increase No change
d. Decrease Increase Decrease Hyperpolarize
e. Increase Increase Decrease Hyperpolarize

a. a
b. b
c. c
d. d
e. e

ANS: B

6. Which of the labeled proteins (shaded) is attached to the membrane by a
glycosylphosphatidylinositol (GPI) anchor?




a. A
b. B
c. C
d. D
e. E

ANS: E




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, Test Bank For Berne & Levy Physiology, 8th Edition
Chapter 01: Principles of Cell Function

7. A cell has channels for Na+, K+, and Cl– in its plasma membrane. The resting
membrane potential is –60 mV (cell interior negative). The intracellular and extracellular
concentrations for these ions, as well as the calculated Nernst potentials, are listed as
follows:
Ion Intracellular Extracellular Ei
Concentration Concentration
Na+ 14 mEq/L 140 mEq/L 60 mV
+
K 150 mEq/L 5 mEq/L –89 mV
Cl– 10 mEq/L 100 mEq/L –60 mV

A drug is applied to the cell that increases the permeability of the cell by Cl– (i.e., it
opens Cl– channels). What effect will this drug have on the net movement of Cl– across
the plasma membrane?
a. Net Cl– movement out of the cell will be increased.
b. Net Cl– movement into the cell will be increased.
c. There will be no change in the net movement of Cl–.

ANS: C

8. Reducing the extracellular [K+] would be expected to have which of the following
effects on the resting membrane potential and on the excitability of ventricular myocytes?
Membrane Potential Excitability
a. Unchanged Unchanged
b. Hyperpolarized Decreased
c. Hyperpolarized Increased
d. Depolarized Decreased
e. Depolarized Increased

a. a
b. b
c. c
d. d
e. e

ANS: B

9. A cell is bathed in an isotonic NaCl solution that contains 5 mmol/L of glucose. The
intracellular concentration of glucose is 10 mmol/L. What is the most likely mechanism
for the transport of glucose across the plasma membrane into this cell?
a. Glucose uniporter
b. Na+-glucose symporter
c. Na+-glucose antiporter
d. Diffusion of glucose through the lipid bilayer of the membrane

ANS: B




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