Question 1

Which of the following best describes the fluid mosaic model of the cell membrane proposed by Singer and Nicolson?

Accepted Answer

A mosaic of proteins embedded in a fluid phospholipid bilayer, with both lipids and proteins able to move laterally.

Question 2

Cholesterol is an important component of animal cell membranes. What is its primary function?

Accepted Answer

It increases membrane fluidity at high temperatures and prevents freezing at low temperatures.

Question 3

Which type of membrane protein is most likely to function as a selective transporter for hydrophilic molecules?

Accepted Answer

Integral transmembrane protein

Question 4

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

Accepted Answer

Water will leave the cell, causing it to shrink.

Question 5

Which equation correctly represents the osmotic pressure ($\Pi$) of a solution, given by van 't Hoff's law?

Accepted Answer

$\Pi = iMRT$

Question 6

Facilitated diffusion differs from simple diffusion in that:

Accepted Answer

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

Question 7

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 8

A mutation causes a cell to produce saturated fatty acids instead of unsaturated fatty acids in its membrane. What is the most likely effect on membrane fluidity?

Accepted Answer

Membrane fluidity will decrease, making the membrane more rigid.

Question 9

Which of the following transport mechanisms can move solutes against their concentration gradient?

Accepted Answer

Active transport

Question 10

The Na+/K+ pump is an example of which type of membrane transport?

Accepted Answer

Active transport using ATP

Question 11

Which of the following statements about aquaporins is correct?

Accepted Answer

Aquaporins are membrane proteins that selectively transport water molecules across the membrane.

Question 12

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

Accepted Answer

Synthesizing DNA within the membrane

Question 13

A cell is placed in an isotonic solution. What will happen to the cell?

Accepted Answer

There will be no net movement of water across the membrane.

Question 14

Which of the following best describes the movement of molecules in simple diffusion?

Accepted Answer

Molecules move freely across the membrane from high to low concentration without energy input.

Question 15

Which of the following is a correct description of a symporter?

Accepted Answer

A transporter that moves two types of solutes in the same direction.

Question 16

Which process is responsible for the movement of water across a semipermeable membrane?

Accepted Answer

Osmosis

Question 17

Which of the following would most likely increase the rate of facilitated diffusion across a membrane?

Accepted Answer

Increasing the number of transporter proteins in the membrane

Question 18

Which of the following is a real-life example of receptor-mediated endocytosis?

Accepted Answer

Liver cell taking up LDL cholesterol from the blood

Question 19

Which of the following statements about glycolipids in the cell membrane is correct?

Accepted Answer

Glycolipids are found in the outer leaflet and serve as cell surface markers.

Question 20

A red blood cell is placed in pure water. Which equation best describes the net movement of water into the cell?

Accepted Answer

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

Membranes and Lipids: Structure and Function (Chapter 5 Study Notes)

Study Guide - Practice Questions

Study Guide - Flashcards