Question 1

Which property of the plasma membrane allows it to regulate the movement of substances into and out of the cell?

Accepted Answer

Its amphipathic nature, with both hydrophobic and hydrophilic regions

Question 2

A cell is placed in a solution with a higher concentration of solutes than inside the cell. What will happen to the cell?

Accepted Answer

It will lose water and shrink due to osmosis

Question 3

Which of the following best describes the role of cholesterol in animal cell membranes?

Accepted Answer

It maintains membrane fluidity by preventing tight packing of phospholipids

Question 4

Which equation correctly represents the movement of water across a selectively permeable membrane due to osmosis?

Accepted Answer

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

Question 5

Facilitated diffusion differs from simple diffusion in that:

Accepted Answer

It requires membrane proteins to transport specific molecules

Question 6

Which type of membrane protein is directly involved in cell-cell recognition?

Accepted Answer

Glycoproteins with attached carbohydrates

Question 7

A neuron releases neurotransmitters into the synaptic cleft. This is an example of:

Accepted Answer

Synaptic signaling

Question 8

Which process requires energy to move substances against their concentration gradient?

Accepted Answer

Active transport

Question 9

The sodium-potassium pump in animal cells uses ATP to exchange ions across the membrane. What is the net result of one cycle?

Accepted Answer

3 Na$^+$ ions out, 2 K$^+$ ions in

Question 10

Which formula best represents the concentration gradient driving passive transport?

Accepted Answer

$\Delta C = C_{high} - C_{low}$

Question 11

A plant cell in a hypotonic solution becomes turgid because:

Accepted Answer

Water enters the cell, and the cell wall prevents bursting

Question 12

Which type of endocytosis involves the engulfment of large particles or cells?

Accepted Answer

Phagocytosis

Question 13

What is the main function of ligand-gated ion channels in cell signaling?

Accepted Answer

They open in response to a signal molecule, allowing ions to flow across the membrane

Question 14

Which of the following is a real-world example of bulk transport across the plasma membrane?

Accepted Answer

White blood cells engulfing bacteria by phagocytosis

Question 15

Which equation describes the electrochemical gradient that drives ion movement across membranes?

Accepted Answer

$\Delta G = RT \ln \left( \frac{[C]_{inside}}{[C]_{outside}} \right) + zF\Delta \Psi$

Question 16

Which type of signaling involves hormones traveling through the bloodstream to reach distant target cells?

Accepted Answer

Endocrine signaling

Question 17

A cell uses a proton pump to create a gradient. This gradient is then used to transport sucrose into the cell. What is this an example of?

Accepted Answer

Cotransport (secondary active transport)

Question 18

Which of the following best explains why unsaturated fatty acids increase membrane fluidity?

Accepted Answer

Their kinked tails prevent tight packing of phospholipids

Question 19

Which step in cell signaling involves the conversion of a signal to a cellular response?

Accepted Answer

Signal transduction

Question 20

A mutation causes a membrane protein to lose its ability to bind to GTP. Which signaling pathway would be directly affected?

Accepted Answer

G protein-coupled receptor pathway

Membrane Transport & Cell Signaling: Structure, Function, and Mechanisms

Study Guide - Practice Questions