Question 1

Which of the following best describes the function of the plasma membrane's selective permeability?

Accepted Answer

It controls which substances can enter and exit the cell based on size and charge.

Question 2

A red blood cell is placed in a hypotonic solution. What will most likely happen to the cell?

Accepted Answer

It will swell and may burst as water enters the cell.

Question 3

Which type of membrane transport requires energy directly from ATP hydrolysis?

Accepted Answer

Primary active transport

Question 4

What is the main difference between primary and secondary active transport?

Accepted Answer

Primary active transport uses ATP directly, while secondary active transport uses energy stored in ion gradients.

Question 5

Which cell junction allows ions and small molecules to pass directly between adjacent cells, facilitating cell-to-cell communication?

Accepted Answer

Gap junctions

Question 6

Which of the following is a function of membrane carbohydrates?

Accepted Answer

They allow cells to recognize each other.

Question 7

A cell is placed in a hypertonic solution. What is the expected outcome?

Accepted Answer

Water will leave the cell, causing it to shrink.

Question 8

Which of the following best explains why phospholipids form a bilayer in water?

Accepted Answer

Their polar heads interact with water, while nonpolar tails avoid water.

Question 9

Which process is responsible for the movement of oxygen ($O_2$) across the plasma membrane?

Accepted Answer

Simple diffusion

Question 10

What is the role of cholesterol in the plasma membrane?

Accepted Answer

It prevents the membrane from becoming too stiff or too fluid.

Question 11

Which of the following is true about facilitated diffusion?

Accepted Answer

It uses membrane proteins to move polar solutes down their concentration gradient.

Question 12

Which equation best represents the hydrolysis of ATP used in primary active transport?

Accepted Answer

$ATP + H_2O \rightarrow ADP + P_i + energy$

Question 13

Which of the following is NOT a function of transmembrane proteins?

Accepted Answer

Synthesizing DNA

Question 14

What is the main function of the Na$^+$-K$^+$ pump?

Accepted Answer

To establish and maintain Na$^+$ and K$^+$ concentration gradients across the plasma membrane

Question 15

Which of the following statements about osmosis is correct?

Accepted Answer

Osmosis is the diffusion of water across the plasma membrane, often through aquaporins.

Question 16

Which process involves the cell taking in large molecules by packaging them into vesicles?

Accepted Answer

Endocytosis

Question 17

Which of the following best describes secondary active transport?

Accepted Answer

It uses the energy stored in an ion gradient to move another solute against its concentration gradient.

Question 18

Which cell junction helps tissues resist pulling forces?

Accepted Answer

Desmosomes

Question 19

Which of the following is true regarding isotonic solutions?

Accepted Answer

Cells placed in isotonic solutions will maintain their normal shape and volume.

Question 20

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

Accepted Answer

Glucose uptake in intestinal cells using the Na$^+$ gradient

The Cell: Plasma Membrane Structure and Function

Study Guide - Practice Questions