Question 1

Which of the following best describes primary active transport across the plasma membrane?

Accepted Answer

It uses ATP hydrolysis to change the shape of a transport protein, moving solutes against their concentration gradient.

Question 2

A patient is diagnosed with a genetic defect in the Na+-K+ ATPase pump. Which of the following cellular consequences is most likely?

Accepted Answer

Loss of resting membrane potential due to inability to maintain ion gradients.

Question 3

Which equation correctly represents the relationship for membrane potential ($V_m$) based on ion concentrations?

Accepted Answer

$V_m = \frac{RT}{F} \ln \left( \frac{[K^+]_{out}}{[K^+]_{in}} \right)$

Question 4

Which of the following is TRUE regarding secondary active transport?

Accepted Answer

It depends on energy stored in ion gradients created by primary active transport.

Question 5

A cell is exposed to a toxin that blocks clathrin-mediated endocytosis. Which process will be most directly affected?

Accepted Answer

Receptor-mediated uptake of LDL cholesterol.

Question 6

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

Accepted Answer

They anchor cells to extracellular matrix and assist in movement and signaling.

Question 7

During phagocytosis, which structure is formed when the cell engulfs a particle?

Accepted Answer

Phagosome

Question 8

Which of the following statements about resting membrane potential (RMP) is correct?

Accepted Answer

RMP is primarily established by the action of the Na+-K+ pump and K+ leakage channels.

Question 9

Which process involves the movement of large particles, macromolecules, and fluids across the membrane in membranous sacs called vesicles?

Accepted Answer

Vesicular transport

Question 10

A neuron rapidly depolarizes its membrane by opening Na+ channels. What is the immediate effect on membrane potential?

Accepted Answer

Membrane potential becomes less negative (depolarizes).

Question 11

Which of the following is a correct example of symporters in secondary active transport?

Accepted Answer

Na+-glucose cotransporter moving both Na+ and glucose into the cell.

Question 12

Which of the following best explains why K+ is the key player in setting the resting membrane potential?

Accepted Answer

K+ is more permeable than Na+ and its concentration and electrical gradients are balanced.

Question 13

Which of the following is NOT a function of plasma membrane receptors?

Accepted Answer

Anchoring cells to the extracellular matrix.

Question 14

Which process is described as 'cell drinking' and involves the uptake of extracellular fluid and dissolved solutes?

Accepted Answer

Pinocytosis

Question 15

A hormone binds to a G protein-linked receptor on the cell membrane. What is the most likely result?

Accepted Answer

Activation of G proteins, which then trigger second messenger pathways.

Question 16

Which of the following is TRUE about exocytosis?

Accepted Answer

It involves the fusion of vesicles with the plasma membrane to release contents outside the cell.

Question 17

Which of the following is a correct statement about caveolae?

Accepted Answer

They are small pits with different protein coat than clathrin, capturing specific molecules for transcytosis.

Question 18

Which of the following best describes the function of SNARE proteins in vesicular transport?

Accepted Answer

They mediate the docking and fusion of vesicles with the plasma membrane.

Question 19

A cell is unable to respond to neurotransmitters due to a defect in ligand-gated ion channels. Which cellular process is most directly impaired?

Accepted Answer

Chemical signaling via plasma membrane receptors.

Cell Membrane Transport, Membrane Potential, and Cell-Environment Interactions

Study Guide - Practice Questions