Question 1

Which of the following best describes the role of glycoproteins in cell recognition and immune response?

Accepted Answer

Glycoproteins display unique carbohydrate chains on the cell surface, allowing the immune system to distinguish self from non-self cells.

Question 2

A patient receives a blood transfusion from a donor with a different blood type. Which molecular feature is most likely to trigger an immune response?

Accepted Answer

Presence of foreign glycoproteins with distinct carbohydrate chains on the donor's red blood cells.

Question 3

Which of the following molecules can most easily diffuse directly through the phospholipid bilayer of a cell membrane?

Accepted Answer

Oxygen ($$\mathrm{O_2$})$$

Question 4

Why are ions such as $$\mathrm{K^+}$$ and $$\mathrm{Na^+}$$ unable to pass directly through the cell membrane?

Accepted Answer

They are hydrophilic and charged, so they are repelled by the hydrophobic interior of the membrane.

Question 5

Facilitated diffusion differs from simple diffusion in that:

Accepted Answer

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

Question 6

Which of the following best explains why water ($$\mathrm{H_2O}) $$can pass through the cell membrane despite being polar?

Accepted Answer

Water is small enough that some molecules can slip through the membrane, and specialized aquaporins facilitate its movement.

Question 7

A cell needs to import glucose, a large polar molecule, from a region of high concentration to low concentration. Which transport mechanism is most likely used?

Accepted Answer

Facilitated diffusion via a carrier protein

Question 8

Which equation best represents the movement of molecules by diffusion?

Accepted Answer

$$J = -D \frac{dC}{dx}$$

Question 9

Active transport is required when a cell moves solutes:

Accepted Answer

Against their concentration gradient, from low to high concentration, using energy (ATP)

Question 10

The sodium-potassium pump is an example of:

Accepted Answer

Active transport

Question 11

Which of the following statements about carrier proteins is TRUE?

Accepted Answer

Carrier proteins can change their shape to move specific molecules across the membrane.

Question 12

Which property of the cell membrane allows small nonpolar molecules to pass through easily?

Accepted Answer

The hydrophobic fatty acid tails

Question 13

A mutation in the gene encoding a glycoprotein receptor prevents HIV from binding to a cell. What is the most likely outcome?

Accepted Answer

The cell will be resistant to HIV infection and will not develop AIDS.

Question 14

Which of the following best describes osmosis?

Accepted Answer

Movement of water across a semipermeable membrane from low solute concentration to high solute concentration

Question 15

Which of the following molecules would have the hardest time crossing the cell membrane without a transport protein?

Accepted Answer

Sodium ion ($$\mathrm{Na^+})$$

Question 16

Which process is described by the movement of molecules from an area of high concentration to an area of low concentration without energy input?

Accepted Answer

Simple diffusion

Question 17

Aquaporins are specialized transport proteins that:

Accepted Answer

Facilitate the rapid movement of water across the cell membrane

Question 18

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

Accepted Answer

Glucose entering muscle cells via a carrier protein

Question 19

Which equation represents the energy required for active transport using ATP?

Accepted Answer

$$\mathrm{ATP} ightarrow \mathrm{ADP} + \mathrm{P_i} + 	ext{energy}$$

Question 20

Which of the following statements about the permeability of the cell membrane is correct?

Accepted Answer

Small nonpolar molecules can pass through the membrane without assistance.

Cell Membranes, Transport, and Glycoproteins: Study Notes for General Biology

Guida di studio - Domande di pratica

Study guide - Flashcard