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

Question 1

Which property of phospholipids is primarily responsible for the spontaneous formation of biological membranes in aqueous environments?

Accepted Answer

Their amphipathic nature, having both hydrophilic heads and hydrophobic tails

Question 2

According to the Fluid Mosaic Model, which statement best describes the arrangement of proteins in the plasma membrane?

Accepted Answer

Proteins are embedded within the phospholipid bilayer and can move laterally

Question 3

Which type of membrane protein is most likely to be involved in cell signaling and recognition, such as the interaction between HIV and CD4 cells?

Accepted Answer

Integral membrane proteins

Question 4

A red blood cell is placed in a hypotonic solution. What is the most likely outcome?

Accepted Answer

The cell will swell and may lyse due to water influx

Question 5

Which equation best describes the movement of molecules during simple diffusion across a membrane?

Accepted Answer

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

Question 6

Which molecule is LEAST likely to cross the plasma membrane without the aid of a transport protein?

Accepted Answer

Na	extsuperscript{+} ion

Question 7

What is the primary function of aquaporin proteins in the plasma membrane?

Accepted Answer

Facilitate rapid movement of water molecules across the membrane

Question 8

Which process requires energy input from ATP to move molecules across the membrane?

Accepted Answer

Active transport

Question 9

A plant cell in a hypertonic solution will most likely experience which phenomenon?

Accepted Answer

Plasmolysis, where the plasma membrane pulls away from the cell wall

Question 10

Which statement best explains why cholesterol is important in animal cell membranes?

Accepted Answer

It modulates membrane fluidity, preventing solidification at low temperatures and excessive fluidity at high temperatures

Question 11

Which type of transport is illustrated by the movement of glucose into intestinal cells via sodium-glucose cotransporters?

Accepted Answer

Cotransport (secondary active transport)

Question 12

During receptor-mediated endocytosis, what is the role of receptor proteins?

Accepted Answer

They specifically bind target molecules and initiate vesicle formation

Question 13

Which of the following best describes facilitated diffusion?

Accepted Answer

Movement of molecules down their concentration gradient with the help of transport proteins, without energy input

Question 14

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

Accepted Answer

Primary active transport

Question 15

Which formula represents the electrochemical gradient for an ion across a membrane?

Accepted Answer

$\Delta G = RT \ln \left( \frac{[C]_	ext{in}}{[C]_	ext{out}} ight) + zF\Delta \Psi$

Question 16

Which process is used by white blood cells to engulf bacteria?

Accepted Answer

Phagocytosis

Question 17

Which of the following is a function of glycoproteins in the plasma membrane?

Accepted Answer

Cell recognition and signaling

Question 18

A cell is placed in an isotonic solution. What will happen to the cell?

Accepted Answer

There will be no net movement of water; the cell remains unchanged

Question 19

Which of the following best describes the role of transport proteins in selective permeability?

Accepted Answer

They allow specific molecules to cross the membrane that cannot pass through the lipid bilayer directly

Question 20

Which process is responsible for the release of neurotransmitters from nerve cells?

Accepted Answer

Exocytosis

Chapter 7- Membrane Structure and Function

Study Guide - Practice Questions