Question 1

Which of the following best describes simple diffusion across a cell membrane?

Accepted Answer

Movement of molecules from high concentration to low concentration driven by random kinetic energy

Question 2

Which factor would most likely increase the rate of diffusion of oxygen across a cell membrane?

Accepted Answer

Increasing the concentration gradient of oxygen across the membrane

Question 3

A cell is placed in a solution with a higher concentration of NaCl than its cytoplasm. The membrane is only permeable to water. What will happen?

Accepted Answer

Water will move out of the cell, causing it to shrink

Question 4

Which equation describes the equilibrium potential for a single ion across a membrane?

Accepted Answer

$$E = \frac{RT}{zF} \ln \left( \frac{[K^+]_{out}}{[K^+]_{in}} \right)$$

Question 5

Which of the following is NOT a factor that influences the rate of diffusion across a cell membrane?

Accepted Answer

Number of mitochondria in the cell

Question 6

If the cell membrane becomes more permeable to Na+, what will happen to the resting membrane potential?

Accepted Answer

It will become less negative

Question 7

Which type of membrane transport requires energy from ATP?

Accepted Answer

Primary active transport

Question 8

What is the main function of the Na+/K+ ATPase pump in maintaining the resting membrane potential?

Accepted Answer

It moves Na+ out of the cell and K+ into the cell against their concentration gradients

Question 9

Which of the following best describes osmosis?

Accepted Answer

Movement of water from an area of low solute concentration to high solute concentration across a semipermeable membrane

Question 10

A neuron’s membrane is permeable only to K+. What is the expected resting membrane potential?

Accepted Answer

Approximately -90 mV

Question 11

Which of the following would increase the permeability of a neuron’s membrane to sodium?

Accepted Answer

Opening more sodium leak channels

Question 12

Which of the following is a form of passive transport?

Accepted Answer

Facilitated diffusion

Question 13

Which of the following would most likely decrease the rate of diffusion of glucose across a cell membrane?

Accepted Answer

Decreasing the concentration gradient of glucose

Question 14

Which of the following is true about the lipid bilayer of the plasma membrane?

Accepted Answer

It is composed mainly of phospholipids and cholesterol

Question 15

Which of the following best explains why large or charged molecules cannot easily diffuse across the plasma membrane?

Accepted Answer

The hydrophobic core of the lipid bilayer repels large or charged molecules

Question 16

Which of the following is a consequence of increasing the number of open potassium channels in a neuron?

Accepted Answer

The membrane potential becomes more negative

Question 17

Which of the following is a function of membrane-associated proteins?

Accepted Answer

Transport of solutes across the membrane

Question 18

Which of the following would most likely result in a cell becoming plasmolyzed?

Accepted Answer

Placing the cell in a hypertonic solution

Question 19

Which of the following is true about the resting membrane potential of most cells?

Accepted Answer

It is negative inside compared with outside

Question 20

Which of the following types of channels can change membrane permeability in response to neurotransmitter binding?

Accepted Answer

Chemically-gated channels

Cellular Physiology Part I: Membrane Transport and Resting Membrane Potential

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