Question 1

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

Accepted Answer

It is a passive, non-energetic process that requires membrane proteins to assist the movement of molecules.

Question 2

Which type of membrane protein forms an aqueous channel to allow the movement of solutes across the membrane?

Accepted Answer

Pore/Channel proteins

Question 3

What type of transport does NOT require the assistance of a membrane protein?

Accepted Answer

Passive diffusion

Question 4

Movement of water across a membrane is facilitated by proteins called _____?

Accepted Answer

Aquaporins

Question 5

Which of the following is TRUE about carrier/transport proteins?

Accepted Answer

They undergo conformational changes to move solutes across the membrane.

Question 6

A patient is suffering from dehydration. Which membrane protein is most directly involved in the rapid movement of water into cells?

Accepted Answer

Aquaporins

Question 7

Which of the following statements about facilitated diffusion is INCORRECT?

Accepted Answer

It requires energy input from ATP.

Question 8

Which protein type is responsible for the selective transport of ions across the cell membrane?

Accepted Answer

Ion channels

Question 9

Facilitated diffusion can be described by which of the following equations for the rate of transport ($$J$$)?

$$J = P 	imes (C_{out} - C_{in})$$

Where $$P is $$permeability and $$C_{out}$$ and $$C_{in}$$ are concentrations outside and inside the cell.

Accepted Answer

This equation describes passive diffusion, not facilitated diffusion.

Question 10

Which of the following scenarios best illustrates the function of a carrier protein?

Accepted Answer

Glucose entering a muscle cell via GLUT transporter after a meal.

Question 11

Which of the following is NOT a characteristic of facilitated diffusion?

Accepted Answer

Movement against the concentration gradient

Question 12

A mutation in the gene encoding aquaporin proteins would most likely affect which physiological process?

Accepted Answer

Water reabsorption in the kidneys

Question 13

Which of the following best explains why facilitated diffusion is considered passive?

Accepted Answer

It does not require cellular energy and moves substances down their concentration gradient.

Question 14

Which of the following would most likely increase the rate of facilitated diffusion?

Accepted Answer

Increasing the number of membrane transport proteins

Question 15

Which of the following is a real-world example of facilitated diffusion in human physiology?

Accepted Answer

Insulin-stimulated glucose uptake in adipose tissue

Facilitated Diffusion and Membrane Transport

Study Guide - Practice Questions