Q: Which of the following equations correctly represents the stoichiometry of the sodium-potassium pump?

$$3\ \mathrm{Na}^+\ \text{out},\ 2\ \mathrm{K}^+\ \text{in}$$

Question 1

Which of the following best describes the function of the plasma membrane in a human cell?

Accepted Answer

It is a flexible, selectively permeable barrier that regulates the movement of substances into and out of the cell.

Question 2

Which of the following is a correct description of the phospholipid bilayer structure of the plasma membrane?

Accepted Answer

Hydrophilic heads face the extracellular and intracellular fluids, while hydrophobic tails are buried inside the membrane.

Question 3

Which of the following cell junctions is most important for preventing the leakage of digestive enzymes between epithelial cells in the intestine?

Accepted Answer

Tight junctions

Question 4

A patient receives an intravenous solution that is hypertonic relative to their red blood cells. What is the most likely effect on the cells?

Accepted Answer

The cells will shrink as water leaves the cells.

Question 5

Which of the following best explains why oxygen and carbon dioxide can easily cross the plasma membrane by simple diffusion?

Accepted Answer

They are small, nonpolar molecules.

Question 6

Which of the following is a function of integral membrane proteins?

Accepted Answer

They act as channels or carriers for transport of substances across the membrane.

Question 7

Which process is responsible for the uptake of cholesterol into cells via specific binding to membrane receptors?

Accepted Answer

Receptor-mediated endocytosis

Question 8

The sodium-potassium pump is an example of which type of membrane transport?

Accepted Answer

Primary active transport

Question 9

Which of the following equations correctly represents the stoichiometry of the sodium-potassium pump?

Accepted Answer

$$3\ \mathrm{Na}^+\ 	ext{out},\ 2\ \mathrm{K}^+\ 	ext{in}$$

Question 10

Which of the following best describes the role of the extracellular matrix (ECM)?

Accepted Answer

It provides structural and biochemical support to surrounding cells.

Question 11

A nerve cell transmits an electrical signal by rapidly changing its membrane potential. Which of the following is most directly responsible for establishing the resting membrane potential?

Accepted Answer

Selective permeability to potassium ions and the activity of the sodium-potassium pump

Question 12

Which of the following statements about osmosis is correct?

Accepted Answer

Water moves from an area of low solute concentration to high solute concentration.

Question 13

Which of the following best describes the function of gap junctions?

Accepted Answer

They allow the passage of ions and small molecules directly between adjacent cells.

Question 14

Which of the following is a key difference between facilitated diffusion and primary active transport?

Accepted Answer

Facilitated diffusion moves substances down their concentration gradient without ATP, while primary active transport moves substances against their gradient using ATP.

Question 15

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

Accepted Answer

It will swell as water enters the cell.

Question 16

Which of the following best describes the function of cell adhesion molecules (CAMs)?

Accepted Answer

They enable cells to adhere to each other and to the extracellular matrix.

Question 17

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

Accepted Answer

Uptake of low-density lipoprotein (LDL) cholesterol by liver cells

Question 18

Which of the following best explains why the inside of a resting cell membrane is negative relative to the outside?

Accepted Answer

Potassium ions diffuse out of the cell more easily than sodium ions diffuse in, and the sodium-potassium pump moves more positive charges out than in.

Question 19

Which of the following is a function of the glycocalyx on the cell surface?

Accepted Answer

It serves as a biological marker for cell recognition.

Question 20

Which of the following best describes the mechanism of secondary active transport?

Accepted Answer

It uses the energy stored in ionic gradients created by primary active transport to move other substances.

Cells: The Living Units – Structure, Function, and Membrane Transport

Study Guide - Practice Questions

Study Guide - Flashcards