$ \text{Water moves from an area of low solute concentration to an area of high solute concentration} $

Question 1

Which of the following best describes the amphipathic nature of phospholipids in the cell membrane?

Accepted Answer

They have both hydrophilic heads and hydrophobic tails.

Question 2

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

Accepted Answer

It will swell and possibly burst because water enters the cell by osmosis.

Question 3

Which of the following statements about membrane fluidity is correct?

Accepted Answer

Increasing the proportion of unsaturated fatty acids increases membrane fluidity.

Question 4

Integral membrane proteins differ from peripheral membrane proteins in that integral proteins:

Accepted Answer

Penetrate the hydrophobic core of the lipid bilayer.

Question 5

Which equation correctly represents the movement of water during osmosis across a selectively permeable membrane?

Accepted Answer

$ 	ext{Water moves from an area of low solute concentration to an area of high solute concentration} $

Question 6

Which of the following best explains why cholesterol is important for membrane fluidity?

Accepted Answer

Cholesterol acts as a buffer, increasing fluidity at low temperatures and decreasing it at high temperatures.

Question 7

A cell uses the sodium-potassium pump to move ions against their concentration gradients. Which of the following best describes this process?

Accepted Answer

Active transport, requiring ATP hydrolysis.

Question 8

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

Accepted Answer

Cell-cell recognition and communication.

Question 9

Which of the following molecules would most easily diffuse through a pure phospholipid bilayer?

Accepted Answer

Oxygen ($ O_2 $)

Question 10

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

Accepted Answer

The cell will lose water and become plasmolyzed.

Question 11

Which of the following best describes facilitated diffusion?

Accepted Answer

Movement of molecules down their concentration gradient via membrane proteins, without energy input.

Question 12

Which of the following is an example of cotransport in cells?

Accepted Answer

Using the proton gradient created by a proton pump to drive the uptake of sucrose.

Question 13

Which of the following best explains why aquaporins are necessary in some cells?

Accepted Answer

They facilitate rapid water movement across the membrane, which would otherwise be too slow.

Question 14

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

Accepted Answer

Storing genetic information.

Question 15

A cell is placed in an unknown solution. After some time, the cell neither swells nor shrinks. What can you conclude about the solution?

Accepted Answer

The solution is isotonic to the cell.

Question 16

Which of the following best describes the effect of temperature on membrane fluidity?

Accepted Answer

Increasing temperature increases membrane fluidity.

Question 17

Which of the following best describes the process of phagocytosis?

Accepted Answer

The cell engulfs large particles or other cells by wrapping the membrane around them.

Question 18

Which of the following is a real-life example of the importance of cell membrane proteins in human health?

Accepted Answer

HIV uses a glycoprotein to bind to CD4/CCR5 receptor proteins on white blood cells, allowing viral entry.

Question 19

Which of the following best explains why the fluid mosaic model is an accurate description of the plasma membrane?

Accepted Answer

It describes the membrane as a dynamic structure with proteins and lipids moving laterally within the bilayer.

Membrane Function and Cellular Transport: Study Notes

Study Guide - Practice Questions