Question 1

Which of the following best describes the arrangement of phospholipids in the cell membrane?

Accepted Answer

Phospholipids form a bilayer with hydrophilic heads facing outward and hydrophobic tails facing inward.

Question 2

What is the primary function of aquaporins in the plasma membrane?

Accepted Answer

Facilitate the rapid movement of water across the membrane.

Question 3

A red blood cell placed in a hypotonic solution will:

Accepted Answer

Burst due to water influx (cytolysis).

Question 4

Which of the following statements about membrane fluidity is correct?

Accepted Answer

Increasing cholesterol concentration buffers membrane fluidity at both high and low temperatures.

Question 5

Which type of membrane protein is most likely to be involved in signal transduction?

Accepted Answer

Integral protein

Question 6

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

Accepted Answer

Primary active transport uses ATP directly, while secondary active transport uses a gradient created by ATP.

Question 7

Which of the following molecules can cross the cell membrane without a transport protein?

Accepted Answer

O2

Question 8

In the sodium-potassium pump, how many sodium ions are transported out of the cell for each cycle?

Accepted Answer

3

Question 9

Which of the following best describes the process of osmosis?

Accepted Answer

Movement of water from an area of low solute concentration to high solute concentration across a membrane.

Question 10

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

Accepted Answer

Synthesis of phospholipids

Question 11

A plant cell placed in a hypertonic solution will:

Accepted Answer

Undergo plasmolysis.

Question 12

Which equation best represents the movement of solutes during diffusion?

Accepted Answer

$ J = -D \frac{dC}{dx} $

Question 13

Which of the following is true about facilitated diffusion?

Accepted Answer

It uses transport proteins to move molecules down their concentration gradient.

Question 14

Which term describes the movement of two substances in opposite directions across a membrane?

Accepted Answer

Antiporter

Question 15

Which process is illustrated by the fusion of a vesicle with the plasma membrane to release its contents outside the cell?

Accepted Answer

Exocytosis

Question 16

Which of the following is a correct statement about glycosylation?

Accepted Answer

It is the addition of carbohydrates to proteins or lipids, important for cell-cell recognition.

Question 17

Which of the following best describes the role of cholesterol in the plasma membrane?

Accepted Answer

Cholesterol acts as a buffer, maintaining membrane fluidity at varying temperatures.

Question 18

Which of the following is an example of receptor-mediated endocytosis?

Accepted Answer

Uptake of LDL cholesterol by cells.

Question 19

Which equation represents the energy requirement for active transport?

Accepted Answer

$ \Delta G = RT \ln \left( \frac{[C]_2}{[C]_1} \right) + zF\Delta \Psi $

Question 20

Which of the following is NOT a type of endocytosis?

Accepted Answer

Exocytosis

Membrane Structure and Function: Study Guide

Study Guide - Practice Questions