Q: Which equation best represents the relationship for the rate of diffusion ($$R) of a $$molecule across a membrane, given concentration difference ($$ riangle C$$), membrane area ($$A$$), and permeability constant ($$P$$)?

$$R = P \times A \times \triangle C$$

Question 1

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

Accepted Answer

It prevents crystallization of fatty acids and decreases membrane fluidity.

Question 2

A cell is placed in a solution and begins to swell. Which term best describes the solution relative to the cell?

Accepted Answer

Hypotonic

Question 3

Which type of membrane protein penetrates the phospholipid bilayer and is amphipathic?

Accepted Answer

Integral protein

Question 4

What is the main force driving passive diffusion across the plasma membrane?

Accepted Answer

Concentration gradient

Question 5

Which of the following would most likely increase the fluidity of a cell membrane?

Accepted Answer

Increasing the proportion of short, unsaturated fatty acids

Question 6

A cell in a hypertonic solution will:

Accepted Answer

Shrivel due to water loss

Question 7

Which of the following statements about facilitated diffusion is correct?

Accepted Answer

It uses channel or carrier proteins to move molecules down their concentration gradient.

Question 8

Which component of the plasma membrane is primarily responsible for cell recognition and adhesion?

Accepted Answer

Oligosaccharides covalently bonded to glycoproteins

Question 9

If the temperature of a cell membrane is increased, what is the expected effect on membrane fluidity?

Accepted Answer

Membrane fluidity will increase.

Question 10

Which of the following best explains why phospholipids form bilayers in aqueous solutions?

Accepted Answer

They are amphipathic, having both hydrophilic and hydrophobic regions.

Question 11

A researcher observes that a cell membrane is less permeable to water than expected. Which component is most likely present in higher amounts?

Accepted Answer

Cholesterol

Question 12

Which equation best represents the relationship for the rate of diffusion ($$R) of a $$molecule across a membrane, given concentration difference ($$	riangle C$$), membrane area ($$A$$), and permeability constant ($$P$$)?

Accepted Answer

$$R = P 	imes A 	imes 	riangle C$$

Question 13

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

Accepted Answer

Forming a selectively permeable barrier

Question 14

Gap junctions in animal cells are primarily involved in:

Accepted Answer

Facilitating communication by allowing passage of ions and small molecules

Question 15

Which of the following molecules can most easily diffuse through the phospholipid bilayer without assistance?

Accepted Answer

Small uncharged molecules like ethanol

Question 16

A cucumber is placed in a warm bath of water. If the bath water is hypertonic to the cucumber cells, what will happen to the cucumber cells?

Accepted Answer

They will lose water and shrivel.

Question 17

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

Accepted Answer

A dynamic arrangement of proteins bobbing in a fluid bilayer of phospholipids.

Question 18

Which type of cell junction restricts membrane protein mobility and seals intercellular spaces?

Accepted Answer

Tight junctions

Question 19

Which of the following statements about osmosis is correct?

Accepted Answer

Water moves from a region of higher water concentration to lower water concentration.

Question 20

Which of the following is a real-world example of facilitated diffusion?

Accepted Answer

Glucose entering a muscle cell via a specific carrier protein

Plasma Membrane Structure and Function: Study Notes for General Biology

Study Guide - Practice Questions

Study Guide - Flashcards