Question 1

Which of the following best describes primary active transport across a cell membrane?

Accepted Answer

It uses a pump protein and requires energy from ATP to move molecules against their concentration gradient.

Question 2

The Na⁺/K⁺ pump is an example of which type of membrane transport?

Accepted Answer

Primary active transport

Question 3

During the operation of the Na⁺/K⁺ pump, what is the net movement of ions per ATP hydrolyzed?

Accepted Answer

3 Na⁺ out, 2 K⁺ in

Question 4

Which equation correctly represents the hydrolysis of ATP during active transport?

Accepted Answer

$\mathrm{ATP} \rightarrow \mathrm{ADP} + \mathrm{P_i}$

Question 5

Which of the following is TRUE regarding secondary active transport?

Accepted Answer

It uses energy from the movement of one ion down its gradient to transport another molecule against its gradient.

Question 6

A patient is given a drug that inhibits the Na⁺/K⁺ pump. What is the most likely immediate effect on intracellular ion concentrations?

Accepted Answer

Intracellular Na⁺ will increase and K⁺ will decrease.

Question 7

Which of the following best explains why water moves across cell membranes during osmosis?

Accepted Answer

Water moves toward areas of higher solute concentration to dilute the solutes.

Question 8

Given the following concentrations from Table 4.1, which solute has a much higher concentration inside the cell compared to outside?

Accepted Answer

K⁺

Question 9

Which of the following transport processes is always passive and does NOT require a protein carrier?

Accepted Answer

Simple diffusion

Question 10

A cell is placed in a solution with a higher concentration of solutes than its cytoplasm. What will happen to the water in the cell?

Accepted Answer

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

Question 11

Which of the following is a feature of mediated transport but NOT simple diffusion?

Accepted Answer

Saturation at high substrate concentrations

Question 12

Which of the following is a real-life example of secondary active transport in the human body?

Accepted Answer

Sodium-linked glucose transport in the intestine

Question 13

Which of the following statements about chemical messengers is CORRECT?

Accepted Answer

Paracrines act on nearby cells by diffusing through the extracellular fluid.

Question 14

Which of the following is an example of a paracrine signaling molecule?

Accepted Answer

Histamine

Question 15

Which of the following best describes the role of the Na⁺/K⁺ pump in maintaining cell homeostasis?

Accepted Answer

It maintains high intracellular K⁺ and low Na⁺ concentrations.

Question 16

Which of the following equations represents the osmotic pressure ($\Pi$) generated by solutes in a solution?

Accepted Answer

$\Pi = iMRT$

Question 17

A mutation causes a cell to lack carrier proteins for glucose. Which transport process will be most affected?

Accepted Answer

Facilitated diffusion of glucose

Question 18

Which of the following is TRUE about gap junctions?

Accepted Answer

They allow direct cytoplasmic communication between adjacent cells.

Question 19

Which of the following is a property of the Na⁺/K⁺ pump that distinguishes it from channel proteins?

Accepted Answer

It demonstrates saturation due to specific binding sites.

Question 20

Which of the following best explains why facilitated diffusion can reach a maximum rate ($V_{max}$)?

Accepted Answer

All carrier proteins become saturated with substrate.

Membrane Transport and Intercellular Communication in Anatomy & Physiology

Study Guide - Practice Questions