Question 1

Which statement best describes the fluid mosaic model of the cell membrane?

Accepted Answer

The membrane consists of a dynamic phospholipid bilayer with embedded proteins that can move laterally.

Question 2

Which of the following best explains why cell membranes are selectively permeable?

Accepted Answer

Only small, nonpolar molecules can pass through the membrane without assistance.

Question 3

A red blood cell placed in a hypotonic solution will:

Accepted Answer

Swell and possibly burst due to water influx.

Question 4

Which process requires energy input from the cell?

Accepted Answer

Active transport

Question 5

Which equation correctly represents the calculation of osmotic pressure ($\Pi$) using van't Hoff's law?

Accepted Answer

$\Pi = iCRT$

Question 6

A cell uses a sodium-potassium pump to maintain its internal environment. Which best describes this process?

Accepted Answer

Active transport using ATP to move sodium out and potassium in against their gradients.

Question 7

Which of the following is NOT a function of integral membrane proteins?

Accepted Answer

Forming the phospholipid bilayer structure.

Question 8

Facilitated diffusion differs from simple diffusion in that:

Accepted Answer

Facilitated diffusion uses membrane proteins to transport molecules down their concentration gradient.

Question 9

Which scenario best illustrates receptor-mediated endocytosis?

Accepted Answer

A cell taking in cholesterol by binding it to specific membrane receptors before internalization.

Question 10

Which of the following statements about osmosis is correct?

Accepted Answer

Osmosis is the passive movement of water across a selectively permeable membrane.

Question 11

A neuron maintains a resting membrane potential by:

Accepted Answer

Using active transport to create an electrochemical gradient.

Question 12

Which of the following best describes pinocytosis?

Accepted Answer

The cell takes in extracellular fluid and dissolved solutes by forming small vesicles.

Question 13

Which term describes the movement of water from an area of low solute concentration to high solute concentration across a membrane?

Accepted Answer

Osmosis

Question 14

Which of the following is a key difference between exocytosis and endocytosis?

Accepted Answer

Exocytosis releases substances from the cell, while endocytosis brings substances into the cell.

Question 15

Which equation best represents the Nernst equation for calculating membrane potential ($E$) for a single ion?

Accepted Answer

$E = \frac{RT}{zF} \ln \left( \frac{[	ext{ion outside}]}{[	ext{ion inside}]} ight)$

Question 16

Which of the following would increase the rate of simple diffusion across a cell membrane?

Accepted Answer

Increasing the temperature.

Question 17

A patient is given intravenous fluids that are isotonic to their blood plasma. What is the expected effect on their red blood cells?

Accepted Answer

Red blood cells will remain unchanged.

Question 18

Which of the following is a function of glycoproteins in the plasma membrane?

Accepted Answer

Acting as cell recognition molecules in immune responses.

Question 19

Which process is most directly responsible for the uptake of large particles, such as bacteria, by immune cells?

Accepted Answer

Phagocytosis

Question 20

A cell is placed in a hypertonic solution. What will happen to the cell?

Accepted Answer

It will shrink due to water loss.

Membrane Biochemistry: Structure and Transport Mechanisms

Study Guide - Practice Questions