Question 1

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

Accepted Answer

It uses a membrane protein to move molecules against their concentration gradient, requiring ATP.

Question 2

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

Accepted Answer

Primary active transport

Question 3

What is the net movement of ions by the Na⁺/K⁺ pump during one cycle?

Accepted Answer

3 Na⁺ out, 2 K⁺ in

Question 4

Which equation best represents the energy requirement for the Na⁺/K⁺ pump?

Accepted Answer

$ATP \rightarrow ADP + P$

Question 5

Secondary active transport relies on which of the following?

Accepted Answer

Energy stored in the electrochemical gradient created by primary active transport

Question 6

Which of the following is true about facilitated diffusion?

Accepted Answer

It uses carrier proteins to move molecules down their concentration gradient.

Question 7

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

Increase in intracellular Na⁺ and decrease in intracellular K⁺

Question 8

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

Accepted Answer

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

Question 9

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

Accepted Answer

Saturation of transport rate at high substrate concentrations

Question 10

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

Accepted Answer

Water will leave the cell by osmosis, causing the cell to shrink.

Question 11

Which of the following is NOT a property of the Na⁺/K⁺ pump?

Accepted Answer

It moves ions down their concentration gradients.

Question 12

Which of the following best describes the role of ATP in primary active transport?

Accepted Answer

ATP provides the energy required to move ions against their concentration gradients.

Question 13

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 14

Which of the following statements about chemical messengers is correct?

Accepted Answer

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

Question 15

Which of the following is an example of a paracrine chemical messenger?

Accepted Answer

Histamine released during inflammation

Question 16

Which of the following best describes the difference between neurotransmitters and hormones?

Accepted Answer

Neurotransmitters are released into the extracellular fluid at synapses, while hormones are released into the blood.

Question 17

Which of the following is a property of simple diffusion?

Accepted Answer

It does not require membrane proteins.

Question 18

Which of the following best explains why the Na⁺/K⁺ pump is considered an enzyme?

Accepted Answer

It catalyzes the hydrolysis of ATP to provide energy for ion transport.

Question 19

Which of the following is a consequence of saturation in mediated transport?

Accepted Answer

Transport rate reaches a maximum even if substrate concentration increases further.

Question 20

Which of the following best describes the direction of water movement during osmosis?

Accepted Answer

From areas of low solute concentration to areas of high solute concentration

Membrane Transport Mechanisms and Intercellular Communication

Study Guide - Practice Questions