$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6 \mathrm{O}_2 \rightarrow 6 \mathrm{CO}_2 + 6 \mathrm{H}_2O + \text{Energy (ATP + heat)}$$

Question 1

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

Accepted Answer

ATP couples exergonic and endergonic reactions by transferring a phosphate group to other molecules.

Question 2

Which equation correctly represents the overall process of aerobic cellular respiration?

Accepted Answer

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6 \mathrm{O}_2 ightarrow 6 \mathrm{CO}_2 + 6 \mathrm{H}_2O + 	ext{Energy (ATP + heat)}$$

Question 3

A scientist is studying an enzyme-catalyzed reaction. Which of the following changes would most likely increase the rate of reaction?

Accepted Answer

Adjusting the pH to the enzyme's optimal value.

Question 4

Which statement about catabolic and anabolic pathways is correct?

Accepted Answer

Catabolic pathways release energy by breaking down complex molecules; anabolic pathways consume energy to build complex molecules.

Question 5

During cellular respiration, which molecule acts as the main electron shuttle, accepting electrons from organic compounds?

Accepted Answer

NAD$

Question 6

Which of the following best explains why enzymes are necessary for metabolic reactions in living cells?

Accepted Answer

Enzymes lower the activation energy ($$E_a) $$required for reactions to occur.

Question 7

Which of the following is an example of energy coupling in cells?

Accepted Answer

The use of ATP hydrolysis to drive the synthesis of glutamine from glutamic acid and ammonia.

Question 8

A patient is given aspirin to reduce pain and inflammation. Which enzyme is inhibited by aspirin?

Accepted Answer

Cyclooxygenase (COX-1/COX-2)

Question 9

Which of the following statements about redox reactions in cellular respiration is correct?

Accepted Answer

Oxidation refers to the loss of electrons, while reduction refers to the gain of electrons.

Question 10

Which of the following best describes the function of the active site of an enzyme?

Accepted Answer

It is the region where the substrate binds and the reaction is catalyzed.

Question 11

Which process is an example of an anabolic pathway?

Accepted Answer

The synthesis of proteins from amino acids.

Question 12

Which of the following statements about the ATP cycle is correct?

Accepted Answer

ATP is regenerated from ADP and phosphate using energy from catabolic reactions.

Question 13

Which of the following is NOT a way that enzymes lower the activation energy ($$E_a) of a $$reaction?

Accepted Answer

Increasing the free energy change ($$\Delta G) of $$the reaction.

Question 14

A metabolic pathway that breaks down glucose in the absence of oxygen is called:

Accepted Answer

Fermentation

Question 15

Which of the following is true about the flow of energy in ecosystems?

Accepted Answer

Energy flows into ecosystems as sunlight and leaves as heat.

Question 16

Which of the following is a correct statement about cofactors and coenzymes?

Accepted Answer

Coenzymes are a type of organic cofactor required for enzyme activity.

Question 17

Which of the following best explains why cellular respiration occurs in multiple steps?

Accepted Answer

To allow for controlled release and harvesting of energy from organic molecules.

Question 18

Which of the following is an example of mechanical work powered by ATP in cells?

Accepted Answer

Movement of motor proteins along cytoskeletal tracks.

Question 19

Which of the following statements about exergonic and endergonic reactions is correct?

Accepted Answer

Exergonic reactions proceed with a net release of free energy and are spontaneous.

Question 20

A cell is observed to have a high rate of glycolysis but low oxygen availability. Which metabolic pathway is most likely being used to generate ATP?

Accepted Answer

Fermentation

Metabolism 1: Energy, Enzymes, and Metabolic Pathways

Study Guide - Practice Questions