Question 1

Which component of the cell membrane is primarily responsible for its fluidity and stability?

Accepted Answer

Cholesterol

Question 2

A researcher observes a protein that spans the entire cell membrane and forms a channel for ions. How should this protein be classified?

Accepted Answer

Integral protein

Question 3

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

Accepted Answer

They have both hydrophilic and hydrophobic regions.

Question 4

A patient has a genetic disorder affecting the glycocalyx of their cells. Which function is most likely to be impaired?

Accepted Answer

Cell recognition and protection

Question 5

Which equation best represents the rate of diffusion ($$J) $$across a cell membrane according to Fick's Law?

Accepted Answer

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

Question 6

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

Accepted Answer

Synthesis of ATP

Question 7

A cell is placed in a solution and swells until it bursts. What type of membrane permeability and solution is most likely responsible?

Accepted Answer

Selectively permeable membrane in a hypotonic solution

Question 8

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

Accepted Answer

A dynamic structure with proteins and lipids moving laterally within the bilayer

Question 9

Which membrane specialization increases surface area for absorption in intestinal cells?

Accepted Answer

Microvilli

Question 10

A cell membrane is described as selectively permeable. What does this mean?

Accepted Answer

It allows some substances to pass while restricting others.

Question 11

Which of the following molecules is most likely to pass directly through the phospholipid bilayer without assistance?

Accepted Answer

Oxygen ($$O_2)$$

Question 12

A mutation causes a cell to lack identity marker proteins. What is a likely consequence?

Accepted Answer

The immune system may attack the cell as foreign.

Question 13

Which of the following is a carbohydrate attached to a lipid in the cell membrane?

Accepted Answer

Glycolipid

Question 14

Which function is most directly associated with membrane proteins that act as channels?

Accepted Answer

Facilitating the movement of ions and molecules across the membrane

Question 15

If a cell membrane loses its cholesterol, what is the most likely effect?

Accepted Answer

The membrane becomes less stable and more permeable.

Question 16

Which of the following best explains why peripheral proteins do not span the entire membrane?

Accepted Answer

They are attached to either the inner or outer surface of the membrane.

Question 17

A cell is exposed to a toxin that destroys its microvilli. What is the most likely consequence?

Accepted Answer

Decreased absorption of nutrients

Question 18

Which of the following is a correct description of the role of the glycocalyx?

Accepted Answer

It provides protection and facilitates cell recognition.

Question 19

Which of the following best describes the difference between integral and peripheral membrane proteins?

Accepted Answer

Integral proteins span the membrane, while peripheral proteins are attached to its surface.

Question 20

A cell membrane is described as 'selectively permeable.' Which equation best represents the net movement of water across the membrane due to osmosis?

Accepted Answer

$$J = L_p (\Delta P - \Delta \pi)$$

Cell Membrane Structure and Function: A Study Guide

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