Question 1

Which of the following best describes the structure of a biological membrane according to the fluid mosaic model?

Accepted Answer

A double layer of phospholipids with proteins embedded and able to move laterally

Question 2

What property of phospholipids is primarily responsible for the formation of the bilayer structure in cell membranes?

Accepted Answer

Their amphipathic nature, with hydrophilic heads and hydrophobic tails

Question 3

Which of the following molecules would most easily diffuse through a pure phospholipid bilayer without the aid of a transport protein?

Accepted Answer

Oxygen ($O_2$)

Question 4

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

Accepted Answer

It will gain water and burst (lyse)

Question 5

Which of the following best explains why cholesterol is important in animal cell membranes?

Accepted Answer

It stabilizes membrane fluidity across temperature changes

Question 6

Which of the following is a function of membrane proteins?

Accepted Answer

Transport, enzymatic activity, signal transduction, cell-cell recognition, intercellular joining, and attachment to the cytoskeleton and ECM

Question 7

A patient is accidentally given pure water intravenously instead of saline. What is the most likely consequence for their red blood cells?

Accepted Answer

The cells will gain water and burst

Question 8

Which of the following statements about facilitated diffusion is correct?

Accepted Answer

It moves substances down their concentration gradient using transport proteins

Question 9

The sodium-potassium pump is an example of which type of membrane transport?

Accepted Answer

Active transport

Question 10

Which of the following best describes cotransport in biological membranes?

Accepted Answer

The active transport of one solute indirectly drives the transport of another solute

Question 11

Which of the following is NOT a type of endocytosis?

Accepted Answer

Exocytosis

Question 12

Familial hypercholesterolemia is caused by a defect in which cellular process?

Accepted Answer

Receptor-mediated endocytosis of LDL cholesterol

Question 13

Which of the following best explains why plant cells do not burst in a hypotonic environment?

Accepted Answer

They have a rigid cell wall that exerts turgor pressure

Question 14

Which of the following equations best represents the electrochemical gradient for an ion across a membrane?

Accepted Answer

$\Delta G = RT \ln \left( \frac{[C]_	ext{in}}{[C]_	ext{out}} ight) + zF\Delta \Psi$

Question 15

Which of the following is a real-world example of the importance of membrane protein specificity?

Accepted Answer

HIV can only infect cells with the CD4 and CCR5 proteins on their surface

Question 16

Which of the following statements about membrane carbohydrates is correct?

Accepted Answer

They function as markers for cell identification

Question 17

A plant cell is placed in a hypertonic solution. What is the most likely outcome?

Accepted Answer

The cell will lose water and undergo plasmolysis

Question 18

Which of the following best explains why membranes are described as 'mosaics'?

Accepted Answer

They contain a variety of proteins, lipids, and carbohydrates arranged in a patchwork

Question 19

Which of the following is true about the sidedness of membranes?

Accepted Answer

The asymmetrical distribution of proteins, lipids, and carbohydrates is established during membrane synthesis in the ER and Golgi apparatus

Question 20

Which of the following best describes the role of aquaporins in the cell membrane?

Accepted Answer

They facilitate the rapid passive movement of water across the membrane

Membrane Structure and Function: Study Notes for Biology Students

Study Guide - Practice Questions