$$\mathrm{ATP} + \mathrm{H}_2\mathrm{O} \rightarrow \mathrm{ADP} + \mathrm{P}_i + \text{energy}$$

Question 1

Which statement best describes the fluid mosaic model of cell membranes?

Accepted Answer

Membranes are composed of a patchwork of diverse proteins embedded in a phospholipid bilayer.

Question 2

A red blood cell is placed in a hypotonic solution. What is the most likely outcome?

Accepted Answer

The cell will swell and may burst as water enters the cell.

Question 3

Which process requires energy input from the cell to move molecules against their concentration gradient?

Accepted Answer

Active transport

Question 4

Which of the following best explains why plant cells do not burst when placed in a hypotonic environment?

Accepted Answer

Plant cells have a rigid cell wall that resists excessive expansion.

Question 5

Which equation correctly represents the first law of thermodynamics?

Accepted Answer

$$\Delta E = q + w$$

Question 6

A cell uses ATP to drive the active transport of sodium ions out of the cell. Which type of cellular work is this?

Accepted Answer

Transport work

Question 7

Which statement about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy required for a reaction to occur.

Question 8

Which of the following is an example of competitive inhibition?

Accepted Answer

A molecule binds to the active site of an enzyme, preventing substrate binding.

Question 9

During cellular respiration, the hydrolysis of ATP releases energy. Which chemical reaction represents this process?

Accepted Answer

$$\mathrm{ATP} + \mathrm{H}_2\mathrm{O} ightarrow \mathrm{ADP} + \mathrm{P}_i + 	ext{energy}$$

Question 10

Which of the following best describes facilitated diffusion?

Accepted Answer

Movement of molecules down their concentration gradient via specific transport proteins, without energy input.

Question 11

A patient is given a drug that acts as a noncompetitive inhibitor for a key metabolic enzyme. What is the most likely effect?

Accepted Answer

The drug binds elsewhere on the enzyme, changing its shape and reducing activity.

Question 12

Which of the following is true about endergonic reactions?

Accepted Answer

They require an input of energy and yield products rich in potential energy.

Question 13

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

Accepted Answer

Facilitating the rapid diffusion of water into and out of cells.

Question 14

Which of the following best describes the role of entropy in biological systems?

Accepted Answer

Entropy is a measure of disorder or randomness in a system.

Question 15

A cell is placed in an isotonic solution. What will happen to the cell?

Accepted Answer

The cell will remain the same size as water moves in and out at equal rates.

Question 16

Which of the following is NOT a way enzymes speed up chemical reactions?

Accepted Answer

Increasing the temperature of the cell to speed up reactions.

Question 17

Which statement about the plasma membrane is correct?

Accepted Answer

It exhibits selective permeability, allowing some substances to cross more easily than others.

Question 18

Which of the following is an example of mechanical work performed by a cell?

Accepted Answer

Contraction of muscle fibers.

Question 19

Which of the following best describes the process of receptor-mediated endocytosis?

Accepted Answer

A cell takes in specific molecules by binding them to membrane receptors and forming a vesicle.

Chapter 5: The Working Cell – Membrane Structure, Function, and Cellular Energy

Study Guide - Practice Questions