Question 1

Which of the following best describes the Fluid-Mosaic Model of the cell membrane?

Accepted Answer

A flexible bilayer of phospholipids with embedded proteins that move laterally.

Question 2

A cell is placed in a hypotonic solution. What will most likely happen to the cell?

Accepted Answer

Water will move into the cell, causing it to swell and possibly burst.

Question 3

Which transport mechanism requires energy input from the cell and moves substances against their concentration gradient?

Accepted Answer

Active transport

Question 4

Which statement best describes the first law of thermodynamics as it applies to living organisms?

Accepted Answer

Energy is transformed from one form to another, but cannot be created or destroyed.

Question 5

A cell uses ATP to drive an endergonic reaction. Which of the following best describes this process?

Accepted Answer

ATP is hydrolyzed, releasing energy that is coupled to the endergonic reaction.

Question 6

Which of the following is an example of an exergonic reaction in living cells?

Accepted Answer

Hydrolysis of ATP to ADP and phosphate

Question 7

If a cell is placed in an isotonic solution, what will happen to the movement of water across the cell membrane?

Accepted Answer

Water will move equally in both directions, resulting in no net change.

Question 8

Which of the following best describes the role of enzymes in biological reactions?

Accepted Answer

Enzymes act as catalysts, lowering the activation energy and speeding up reactions.

Question 9

A graph of an exergonic reaction shows the energy of reactants and products. Which equation correctly represents the change in free energy ($$\Delta G) $$for an exergonic reaction?

Accepted Answer

$$\Delta G = G_{reactants} - G_{products}$$, and $$\Delta G is $$negative.

Question 10

Which of the following best illustrates the concept of entropy as described by the second law of thermodynamics?

Accepted Answer

Heat released during cellular respiration increases disorder in the environment.

Question 11

Which of the following statements about ATP and ADP is correct?

Accepted Answer

ATP has higher energy than ADP due to its third phosphate group.

Question 12

Which scenario best demonstrates energy coupling in a cell?

Accepted Answer

The hydrolysis of ATP is used to drive the synthesis of glucose from carbon dioxide.

Question 13

Which of the following is NOT a characteristic of enzymes?

Accepted Answer

Enzymes are consumed during the reaction.

Question 14

Which term describes a molecule that binds to an enzyme's active site and prevents substrate binding?

Accepted Answer

Competitive inhibitor

Question 15

A cell needs to import a large molecule, such as a protein, from its environment. Which transport mechanism will it most likely use?

Accepted Answer

Endocytosis

Question 16

Which of the following would most likely increase the rate of an enzyme-catalyzed reaction, assuming all other factors are optimal?

Accepted Answer

Increasing substrate concentration up to the point of enzyme saturation.

Question 17

Which of the following best describes the mechanism of allosteric inhibition?

Accepted Answer

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

Question 18

A cell is placed in a hypertonic solution. What is the expected movement of water?

Accepted Answer

Water will move out of the cell, causing it to shrink.

Question 19

Which of the following is true about facilitated diffusion?

Accepted Answer

It uses membrane proteins to move substances down their concentration gradient.

Question 20

Which of the following best describes feedback inhibition in enzyme regulation?

Accepted Answer

The end product of a metabolic pathway inhibits an earlier enzyme in the pathway.

Chapter 5: The Working Cell – Study Guide and Key Concepts

Study Guide - Practice Questions

Study Guide - Flashcards