Question 1

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

Accepted Answer

They have both a hydrophilic (polar) head and a hydrophobic (nonpolar) tail.

Question 2

A patient is diagnosed with a genetic disorder that affects the structure of their plasma membrane, making it less fluid. Which component is most likely altered?

Accepted Answer

Phospholipids

Question 3

Which of the following molecules can most easily diffuse through the plasma membrane without the aid of a protein channel?

Accepted Answer

Oxygen ($$O_2)$$

Question 4

During receptor-mediated endocytosis, what is the primary role of the receptor proteins on the plasma membrane?

Accepted Answer

To specifically bind and internalize certain extracellular molecules

Question 5

Which of the following best explains why viruses often hijack the endocytic pathway of host cells?

Accepted Answer

To gain entry into the cell by mimicking molecules that are normally internalized

Question 6

A scientist measures the rate of diffusion of a solute across a membrane. Which of the following equations best represents the relationship between the rate of diffusion ($$J) $$and the concentration gradient ($$\Delta C$$)?

Accepted Answer

$$J = P 	imes \Delta C$$

Question 7

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

Accepted Answer

Synthesizing proteins for the cell

Question 8

A dialysis membrane is used in a laboratory to separate molecules based on size. Which of the following statements is correct regarding what can pass through the membrane?

Accepted Answer

Small molecules like glucose can pass, but large proteins cannot.

Question 9

Which of the following best describes the process of exocytosis?

Accepted Answer

Vesicles fuse with the plasma membrane to release their contents outside the cell.

Question 10

Which of the following is a real-life example of regulated exocytosis?

Accepted Answer

Release of insulin from pancreatic beta cells in response to high blood glucose

Question 11

Which of the following factors would NOT increase the rate of diffusion across a plasma membrane?

Accepted Answer

Decreasing the temperature of the solution

Question 12

Which of the following best explains why aquaporins are necessary in the plasma membrane?

Accepted Answer

They facilitate the rapid movement of water molecules across the membrane.

Question 13

A cell is placed in a solution with a higher concentration of solute than inside the cell. Which direction will water move, and by what process?

Accepted Answer

Water will move out of the cell by osmosis.

Question 14

Which of the following is a key difference between phagocytosis and pinocytosis?

Accepted Answer

Phagocytosis involves the engulfment of large particles, while pinocytosis involves the uptake of fluids and small molecules.

Question 15

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

Accepted Answer

A dynamic structure where phospholipids and proteins can move laterally within the layer.

Question 16

Which of the following is a function of the extracellular matrix (ECM) in tissues?

Accepted Answer

Providing structural support to cells and tissues

Question 17

A mutation causes a cell to lack functional integral proteins in its plasma membrane. Which process would be most directly affected?

Accepted Answer

Carrier-mediated transport

Question 18

Which of the following best explains why glucose cannot freely diffuse across the plasma membrane?

Accepted Answer

Glucose is a large, polar molecule and requires a carrier protein to cross the membrane.

Question 19

Which of the following scenarios best illustrates selective permeability of the plasma membrane?

Accepted Answer

Oxygen diffuses into the cell while sodium ions require a channel protein.

Question 20

A cell is observed to engulf bacteria by extending its plasma membrane around them. Which process is being described?

Accepted Answer

Phagocytosis

Physio: Cell Structure and Membrane Transport

Guida di studio - Domande di pratica

Study guide - Flashcard