Question 1

Which of the following best describes the 'fluid' aspect of the fluid mosaic model of the plasma membrane?

Accepted Answer

The ability of phospholipids and some proteins to move laterally within the layer

Question 2

A red blood cell is placed in a solution and it bursts. Which of the following best describes the tonicity of the solution and the process that occurred?

Accepted Answer

The solution is hypotonic; water entered the cell by osmosis

Question 3

Which of the following changes would most likely increase the fluidity of a cell membrane at low temperatures?

Accepted Answer

Increasing the proportion of unsaturated fatty acids in phospholipids

Question 4

Which of the following is NOT a function of membrane proteins?

Accepted Answer

Synthesis of ATP from ADP and phosphate

Question 5

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

Accepted Answer

The cell will become plasmolyzed as water leaves the cell

Question 6

Which of the following statements about facilitated diffusion is correct?

Accepted Answer

It requires a transport protein and moves substances down their concentration gradient

Question 7

Which of the following best explains why the plasma membrane is selectively permeable?

Accepted Answer

The hydrophobic core of the lipid bilayer prevents passage of most polar molecules, while specific proteins allow selective transport

Question 8

Which process is responsible for the uptake of large particles, such as bacteria, by a white blood cell?

Accepted Answer

Phagocytosis

Question 9

A cell uses the sodium-potassium pump to move sodium ions out and potassium ions in. Which of the following statements about this process is correct?

Accepted Answer

It is an example of active transport because it moves ions against their concentration gradients using ATP

Question 10

Which of the following best describes the role of cholesterol in the plasma membrane at high temperatures?

Accepted Answer

Cholesterol decreases membrane fluidity by restraining phospholipid movement

Question 11

Which of the following scenarios best illustrates osmosis?

Accepted Answer

Water moving from an area of low solute concentration to high solute concentration across a semipermeable membrane

Question 12

Which of the following statements about bulk transport is correct?

Accepted Answer

Exocytosis is the process by which cells secrete large molecules by the fusion of vesicles with the plasma membrane

Question 13

Which of the following best describes an amphipathic molecule?

Accepted Answer

A molecule that has both hydrophobic and hydrophilic regions

Question 14

A U-tube is divided by a membrane permeable only to water. Side A contains a 0.5 M sucrose solution, and side B contains a 1.0 M sucrose solution. What will happen to the water level on each side over time?

Accepted Answer

Water will move from side A to side B, causing the water level to rise on side B

Question 15

Which of the following is true regarding the movement of molecules 'down a concentration gradient'?

Accepted Answer

Molecules move from an area of higher concentration to an area of lower concentration

Question 16

Which of the following best distinguishes between passive and active transport?

Accepted Answer

Passive transport does not require energy, while active transport requires energy in the form of ATP

Question 17

Which of the following is an example of receptor-mediated endocytosis?

Accepted Answer

A liver cell taking up LDL cholesterol particles from the blood via specific surface receptors

Question 18

Which of the following best describes the response of a plant cell in an isotonic solution?

Accepted Answer

The cell becomes flaccid due to no net movement of water

Question 19

Which of the following statements about osmosis is correct?

Accepted Answer

Osmosis is the diffusion of water across a selectively permeable membrane

Question 20

Which of the following best explains why integral membrane proteins are amphipathic?

Accepted Answer

They have hydrophobic regions that interact with the membrane interior and hydrophilic regions that interact with the aqueous environment

Chapter 7: Membrane Structure and Function – Guided Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard