Q: Which equation correctly represents the net movement of water during osmosis?

$$\text{Net movement of water} = \text{from low solute concentration to high solute concentration}$$

Question 1

Which of the following best describes the amphipathic nature of phospholipids in the cell membrane?

Accepted Answer

They have both hydrophilic heads and hydrophobic tails, allowing them to form a bilayer in aqueous environments.

Question 2

A red blood cell is placed in a solution with a solute concentration higher than that inside the cell. What will most likely happen to the cell, and what is this process called?

Accepted Answer

The cell will shrink due to water loss; this process is called crenation.

Question 3

Which of the following molecules can most easily cross the plasma membrane without the help of a transport protein?

Accepted Answer

Oxygen ($$O_2)$$

Question 4

Which type of membrane protein is responsible for binding specific signaling molecules and initiating a cellular response?

Accepted Answer

Receptor protein

Question 5

A plant cell is placed in a hypotonic solution. What is the most likely outcome, and what is the physiological significance for the plant?

Accepted Answer

The cell will swell, creating turgor pressure that helps maintain structural support.

Question 6

Which of the following best explains why fish living in cold environments have a higher proportion of unsaturated fatty acids in their cell membranes?

Accepted Answer

Unsaturated fatty acids increase membrane fluidity, preventing the membrane from becoming too rigid at low temperatures.

Question 7

Which equation correctly represents the net movement of water during osmosis?

Accepted Answer

$$	ext{Net movement of water} = 	ext{from low solute concentration to high solute concentration}$$

Question 8

Which of the following is an example of active transport across the cell membrane?

Accepted Answer

The sodium-potassium pump ($$Na^+/K^+$$ pump) moving $$Na^+$$ out and $$K^+ in $$against their concentration gradients using ATP.

Question 9

A patient with a genetic mutation lacks functional LDL (low-density lipoprotein) receptors on their cell membranes. Which process is directly impaired?

Accepted Answer

Receptor-mediated endocytosis

Question 10

Which of the following best describes the role of cholesterol in the plasma membrane at body temperature?

Accepted Answer

It reduces membrane fluidity by restraining phospholipid movement.

Question 11

Which type of cell junction is most important in tissues that act as barriers, such as the lining of the intestine?

Accepted Answer

Tight junctions

Question 12

Which of the following best explains why polar molecules require transport proteins to cross the plasma membrane?

Accepted Answer

The hydrophobic core of the phospholipid bilayer prevents polar molecules from diffusing through.

Question 13

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

Accepted Answer

Cell identification and recognition

Question 14

A white blood cell engulfs a bacterium by surrounding it with its plasma membrane, forming a vesicle. What is this process called?

Accepted Answer

Phagocytosis

Question 15

Which of the following best describes the function of aquaporins in the cell membrane?

Accepted Answer

They facilitate the rapid movement of water across the membrane.

Question 16

Which of the following equations best represents the maintenance of the electrochemical gradient by the sodium-potassium pump?

Accepted Answer

$$3\ Na^+_{	ext{out}} : 2\ K^+_{	ext{in}}$$

Question 17

Which of the following is a real-life example of facilitated diffusion?

Accepted Answer

Glucose entering a muscle cell via a specific carrier protein

Question 18

Which of the following best explains why plant cells do not burst when placed in a hypotonic solution, unlike animal cells?

Accepted Answer

The rigid cell wall provides structural support and prevents bursting.

Question 19

Which of the following best describes the function of gap junctions in animal cells?

Accepted Answer

They allow direct communication and passage of ions between adjacent cells.

Question 20

A patient is given an intravenous solution that is hypertonic relative to their red blood cells. What is the most likely effect on the red blood cells, and why?

Accepted Answer

The cells will lose water and shrink because water moves out to the area of higher solute concentration.

Cell Membrane Structure and Transport Mechanisms: Foundations for Nutrition Science

Guida di studio - Domande di pratica

Study guide - Flashcard