Question 1

Which of the following best describes the structure of a biological membrane according to the fluid mosaic model?

Accepted Answer

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

Question 2

A red blood cell is placed in a solution and swells until it bursts. Which type of solution was the cell placed in, and what process caused this outcome?

Accepted Answer

Hypotonic solution; osmosis

Question 3

Which of the following statements about passive transport is correct?

Accepted Answer

It relies on the random movement of molecules and does not require energy input.

Question 4

Which of the following best explains why enzymes are specific to their substrates?

Accepted Answer

Enzymes have active sites with unique shapes that fit only specific substrates.

Question 5

A cell uses $$\mathrm{Na^+/K^+}$$ pumps to move sodium ions out and potassium ions in, both against their concentration gradients. Which type of transport is this, and what is required for it to occur?

Accepted Answer

Active transport; requires ATP

Question 6

Which of the following is an example of energy coupling in cellular metabolism?

Accepted Answer

Using the energy released from ATP hydrolysis to drive the synthesis of glucose

Question 7

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

Accepted Answer

Cells will shrink as water leaves the cells

Question 8

Which of the following best describes the process of facilitated diffusion?

Accepted Answer

Movement of molecules through a membrane via specific transport proteins, down their concentration gradient

Question 9

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

Accepted Answer

Storing genetic information

Question 10

A cell is observed to engulf large particles by wrapping its plasma membrane around them and forming a vesicle. Which process is being described?

Accepted Answer

Endocytosis

Question 11

Which of the following best explains why competitive inhibitors decrease enzyme activity?

Accepted Answer

They bind to the active site, preventing the substrate from binding.

Question 12

Which equation correctly represents the hydrolysis of ATP?

Accepted Answer

$$\mathrm{ATP + H_2O \rightarrow ADP + P_i + energy}$$

Question 13

Which of the following scenarios best illustrates the concept of selective permeability in a cell membrane?

Accepted Answer

Oxygen and carbon dioxide pass freely, but ions require specific channels to cross.

Question 14

A scientist adds a noncompetitive inhibitor to an enzyme-catalyzed reaction. What is the most likely effect?

Accepted Answer

The inhibitor binds to a site other than the active site, changing the enzyme's shape and reducing activity.

Question 15

Which of the following best describes osmosis?

Accepted Answer

The diffusion of water across a selectively permeable membrane from low solute concentration to high solute concentration

Question 16

Which of the following is an example of potential energy in a biological system?

Accepted Answer

A molecule of glucose before it is broken down in cellular respiration

Question 17

Which of the following best explains why water balance between cells and their surroundings is crucial for organisms?

Accepted Answer

Imbalances can cause cells to shrink or swell, disrupting cellular function.

Question 18

A cell is placed in a solution and neither gains nor loses water. What can you conclude about the solution?

Accepted Answer

It is isotonic to the cell.

Question 19

Which of the following best describes the role of ATP in cellular work?

Accepted Answer

ATP provides energy by transferring a phosphate group to other molecules.

Question 20

Which of the following is a real-world example of exocytosis?

Accepted Answer

A nerve cell releasing neurotransmitters into a synapse

Study Guide: The Working Cell (General Biology)

Guida di studio - Domande di pratica

Study guide - Flashcard