Question 1

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

Accepted Answer

The membrane consists of a fluid bilayer of phospholipids with proteins and carbohydrates embedded or attached, allowing lateral movement.

Question 2

Which of the following molecules can most easily cross the plasma membrane without the aid of a transport protein?

Accepted Answer

Oxygen ($\mathrm{O_2}$)

Question 3

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

Accepted Answer

The cell will gain water and burst (lyse).

Question 4

Which type of membrane protein is most likely to function as a channel for ions to pass through the membrane?

Accepted Answer

Integral transmembrane protein

Question 5

What is the primary function of the sodium-potassium pump in animal cells?

Accepted Answer

To actively transport sodium ions out of the cell and potassium ions into the cell, maintaining concentration gradients.

Question 6

Which equation best represents the net movement of water during osmosis?

Accepted Answer

$\Delta \Psi = \Psi_{outside} - \Psi_{inside}$

Question 7

Which process requires energy input from the cell to move substances against their concentration gradient?

Accepted Answer

Active transport

Question 8

A cell uses exocytosis to secrete insulin. Which organelle is most directly involved in packaging insulin for secretion?

Accepted Answer

Golgi apparatus

Question 9

Which of the following best explains why phospholipids form bilayers in aqueous environments?

Accepted Answer

Phospholipids have hydrophilic heads and hydrophobic tails, causing them to arrange with heads facing water and tails facing inward.

Question 10

Which type of transport protein undergoes a conformational change to move its substrate across the membrane?

Accepted Answer

Carrier protein

Question 11

A patient receives an intravenous solution that is hypertonic compared to their blood cells. What is the expected effect on the blood cells?

Accepted Answer

Cells will lose water and shrink.

Question 12

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

Accepted Answer

Energy storage

Question 13

Which process is used by white blood cells to engulf bacteria?

Accepted Answer

Phagocytosis

Question 14

Which of the following best describes facilitated diffusion?

Accepted Answer

Movement of hydrophilic molecules down their concentration gradient via transport proteins.

Question 15

Which equation describes the energy supplied by ATP hydrolysis for active transport?

Accepted Answer

$\Delta G = \Delta G^\circ + RT \ln \dfrac{[ADP][P_i]}{[ATP]}$

Question 16

Which of the following is true regarding membrane carbohydrates?

Accepted Answer

They are involved in cell-cell recognition and can form glycoproteins or glycolipids.

Question 17

Which process allows cells to take in large quantities of fluid and dissolved substances?

Accepted Answer

Pinocytosis

Question 18

A mutation causes a membrane protein to lose its ability to bind to the cytoskeleton. Which cellular function is most likely to be affected?

Accepted Answer

Cell shape maintenance

Question 19

Which of the following best explains why saturated hydrocarbon tails decrease membrane fluidity?

Accepted Answer

They pack tightly, increasing membrane viscosity and reducing fluidity.

Question 20

Which type of endocytosis is most specific for the uptake of particular molecules?

Accepted Answer

Receptor-mediated endocytosis

Membrane Structure and Function: Study Notes for General Biology

Study Guide - Practice Questions