Question 1

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

Accepted Answer

A dynamic structure where proteins and lipids move laterally within the bilayer.

Question 2

What is the primary function of transport proteins in the plasma membrane?

Accepted Answer

To facilitate the diffusion of polar or charged substances across the membrane.

Question 3

Which process describes the movement of water across a selectively permeable membrane due to differences in solute concentration?

Accepted Answer

Osmosis

Question 4

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

Accepted Answer

It will gain water and become turgid.

Question 5

Which equation best represents the tendency of particles to spread out evenly in an available space (diffusion)?

Accepted Answer

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

Question 6

Dr. Agre received the Nobel Prize for discovering which type of membrane protein?

Accepted Answer

Aquaporins

Question 7

Which of the following statements about facilitated diffusion is correct?

Accepted Answer

It moves substances down their concentration gradient.

Question 8

During active transport, which equation describes the energy required to move ions against their concentration gradient?

Accepted Answer

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

Question 9

Which process involves the engulfment of large particles or cells by the plasma membrane?

Accepted Answer

Phagocytosis

Question 10

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

Accepted Answer

The cell will lose water and shrink.

Question 11

Which of the following best explains why only 'free' water molecules move across a selectively permeable membrane during osmosis?

Accepted Answer

Bound water molecules are attached to solutes and cannot pass through the membrane.

Question 12

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

Accepted Answer

Synthesizing DNA

Question 13

Which process requires a significant alteration of the cell's surface due to changes in the cytoskeleton?

Accepted Answer

Exocytosis and endocytosis

Question 14

Which of the following best describes the role of ATP in active transport?

Accepted Answer

ATP provides the energy to move substances against their concentration gradient.

Question 15

Which scenario best illustrates the concept of membrane selectivity?

Accepted Answer

A cell allows glucose to enter but restricts sodium ions.

Question 16

Which of the following is a critical step in the origin of life according to the study materials?

Accepted Answer

The spontaneous formation of membrane-enclosed collections of molecules.

Question 17

Which equation would you use to calculate the osmotic pressure exerted by solutes in a solution?

Accepted Answer

$ \Pi = iMRT $

Question 18

Which of the following statements about tonicity is correct?

Accepted Answer

Tonicity determines the direction and extent of diffusion based on solute concentration.

Question 19

Which type of transport is illustrated when a cell uses energy to move sodium ions out and potassium ions in, against their concentration gradients?

Accepted Answer

Active transport

Question 20

Which of the following is true regarding the movement of water through aquaporins?

Accepted Answer

Aquaporins allow rapid diffusion of water into and out of cells.

Membrane Structure, Function, and Transport in Cells

Study Guide - Practice Questions