Question 1

Which of the following best describes the structure of a phospholipid in the plasma membrane?

Accepted Answer

A molecule with a polar head and two nonpolar tails.

Question 2

The fluid mosaic model of the plasma membrane states that:

Accepted Answer

Membranes are dynamic mosaics of lipids and proteins that can move laterally.

Question 3

Which component of the plasma membrane is primarily responsible for its selective permeability?

Accepted Answer

The phospholipid bilayer.

Question 4

What is the main function of cholesterol in animal cell membranes?

Accepted Answer

It stabilizes membrane fluidity across temperature changes.

Question 5

A red blood cell placed in a hypertonic solution will:

Accepted Answer

Shrink as water leaves the cell.

Question 6

Which equation correctly represents the movement of water during osmosis?

Accepted Answer

$$\Psi_{water}$$ moves from high to low water potential$

Question 7

Facilitated diffusion differs from simple diffusion in that:

Accepted Answer

Facilitated diffusion uses transport proteins to move molecules down their concentration gradient.

Question 8

Which of the following is an example of active transport?

Accepted Answer

Sodium-potassium pump moving Na$$^+$$ out and K$$^+ in $$against their gradients.

Question 9

The Na$$^+/K$^+$$ pump moves ions across the membrane by:

Accepted Answer

Using ATP to move Na$$^+$$ out and K$$^+ in $$against their concentration gradients.

Question 10

Which process is used by immune cells to engulf bacteria?

Accepted Answer

Phagocytosis

Question 11

A cell in an isotonic solution will:

Accepted Answer

Maintain its shape with no net water movement.

Question 12

Which of the following best explains why polar molecules cannot easily cross the plasma membrane?

Accepted Answer

The nonpolar tails of phospholipids repel polar molecules.

Question 13

Which of the following is a function of membrane carbohydrates?

Accepted Answer

Cell recognition and signaling.

Question 14

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

Accepted Answer

To bind specific molecules and trigger vesicle formation.

Question 15

Which equation best represents the energy requirement for active transport?

Accepted Answer

$$\Delta G \u003e 0$$

Question 16

Which of the following is a consequence of water intoxication in humans?

Accepted Answer

Hypotonic blood plasma causing cells to swell and potentially burst.

Question 17

Which of the following statements about membrane proteins is correct?

Accepted Answer

Membrane proteins can function as transporters, receptors, or enzymes.

Question 18

Which process describes the release of neurotransmitters from a neuron?

Accepted Answer

Exocytosis

Question 19

A plant cell placed in distilled water will become:

Accepted Answer

Turgid

Question 20

Which of the following best explains why viruses such as SARS-CoV-2 can enter cells?

Accepted Answer

They trigger receptor-mediated endocytosis by binding to specific cell surface proteins.

Chapter 7 - Part 1 Study Notes : Membrane Structure and Function: Study Notes for General Biology

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