Question 1

Which of the following best describes the structure of the plasma membrane according to the Fluid Mosaic Model?

Accepted Answer

A double layer of phospholipids with proteins embedded and able to move laterally.

Question 2

Which component of the plasma membrane acts as a 'fluidity buffer,' helping to maintain membrane fluidity at different temperatures?

Accepted Answer

Cholesterol

Question 3

A red blood cell is placed in a solution and begins to shrink. Which of the following best describes the tonicity of the solution relative to the cell?

Accepted Answer

Hypertonic

Question 4

Which of the following molecules is most likely to diffuse directly through the phospholipid bilayer without the aid of a transport protein?

Accepted Answer

Oxygen ($O_2$)

Question 5

Which process requires energy input in the form of ATP to move substances across the plasma membrane?

Accepted Answer

Active transport

Question 6

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

Accepted Answer

The cell will gain water and become turgid.

Question 7

Which of the following best explains why ions such as $Na^+$ and $K^+$ require transport proteins to cross the plasma membrane?

Accepted Answer

They are charged and cannot pass through the hydrophobic core of the membrane.

Question 8

Which of the following is an example of cotransport in membrane transport?

Accepted Answer

Glucose being transported into a cell along with $H^+$ ions, where $H^+$ moves down its gradient and glucose moves against its gradient.

Question 9

During exocytosis, which of the following events occurs?

Accepted Answer

A vesicle fuses with the plasma membrane and releases its contents outside the cell.

Question 10

Which of the following best describes the role of signal transduction in cell signaling?

Accepted Answer

It is the process by which a cell converts an extracellular signal into an intracellular response.

Question 11

A cell is placed in an isotonic solution. What will happen to the cell's volume over time?

Accepted Answer

It will remain the same as there is no net movement of water.

Question 12

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

Accepted Answer

Serving as channels or carriers for specific molecules across the membrane.

Question 13

Which of the following best explains why facilitated diffusion is considered a form of passive transport?

Accepted Answer

It moves molecules down their concentration gradient without energy input.

Question 14

Which of the following scenarios would most likely result in plasmolysis in a plant cell?

Accepted Answer

Placing the cell in a hypertonic solution.

Question 15

Which equation best represents the direction of water movement during osmosis?

Accepted Answer

$	ext{Water moves from an area of low solute concentration to high solute concentration}$

Question 16

Which of the following is NOT a step in the general process of cell signaling?

Accepted Answer

Protein synthesis

Question 17

A patient is given an intravenous solution that is hypotonic relative to their blood cells. What is the most likely consequence?

Accepted Answer

Their blood cells will swell and may burst due to water gain.

Question 18

Which of the following best describes the function of carrier proteins in the plasma membrane?

Accepted Answer

They bind to specific molecules and change shape to transport them across the membrane.

Question 19

Which of the following statements about the sodium-potassium pump is correct?

Accepted Answer

It uses ATP to move $3\ Na^+$ out of the cell and $2\ K^+$ into the cell against their concentration gradients.

Question 20

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

Accepted Answer

Uptake of cholesterol by animal cells via LDL receptors.

Membrane Transport and Cell Signaling: Chapter 5 Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards