Question 1

Which of the following best describes the difference between catabolic and anabolic pathways in metabolism?

Accepted Answer

Catabolic pathways break down molecules and release energy, while anabolic pathways build molecules and require energy input.

Question 2

Which law of thermodynamics states that energy cannot be created or destroyed, only transformed or transferred?

Accepted Answer

First law of thermodynamics

Question 3

A chemical reaction has a negative change in Gibbs free energy ($$\Delta G \u003c 0). $$What does this indicate about the reaction?

Accepted Answer

The reaction is spontaneous and exergonic.

Question 4

Which of the following statements about enzymes is TRUE?

Accepted Answer

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

Question 5

Which of the following best explains why increasing temperature generally increases the rate of enzyme-catalyzed reactions up to a point?

Accepted Answer

Higher temperature increases the kinetic energy of molecules, leading to more frequent and effective collisions.

Question 6

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

Accepted Answer

The use of ATP hydrolysis to drive an endergonic reaction.

Question 7

In a redox reaction, what happens to the molecule that is oxidized?

Accepted Answer

It loses electrons and releases energy.

Question 8

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

Accepted Answer

ATP provides energy for cellular activities by transferring a phosphate group to target molecules.

Question 9

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

Accepted Answer

The inhibitor binds to the active site, preventing substrate binding.

Question 10

Which of the following is a correct statement about feedback inhibition in metabolic pathways?

Accepted Answer

The final product of the pathway inhibits an enzyme earlier in the pathway.

Question 11

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 12

Which of the following is TRUE about the effect of pH on enzyme activity?

Accepted Answer

Each enzyme has an optimal pH at which its activity is highest.

Question 13

A reaction has $$\Delta H  0. $$According to the Gibbs free energy equation $$\Delta G = \Delta H - T\Delta S$$, what can you conclude about the spontaneity of the reaction?

Accepted Answer

The reaction is always spontaneous.

Question 14

Which of the following is NOT a way that enzymes can be regulated?

Accepted Answer

Permanent destruction of the enzyme's active site by substrate binding

Question 15

Which of the following statements about metabolic pathways is correct?

Accepted Answer

Metabolic pathways consist of a series of reactions, each catalyzed by a different enzyme.

Question 16

Which of the following best describes the effect of substrate concentration on the rate of an enzyme-catalyzed reaction?

Accepted Answer

The reaction rate increases with substrate concentration but eventually plateaus when the enzyme is saturated.

Question 17

Which of the following is a real-world example of an exergonic reaction?

Accepted Answer

Hydrolysis of ATP to ADP and inorganic phosphate

Question 18

Which of the following molecules is an electron carrier that is reduced during cellular respiration?

Accepted Answer

NAD+

Question 19

Which of the following best explains why phosphorylation of a molecule by ATP increases its potential energy?

Accepted Answer

The addition of a phosphate group introduces negative charges that repel each other, raising the molecule's potential energy.

Question 20

Which of the following is an example of a coenzyme required for enzyme function?

Accepted Answer

NADH

Chapter 8: Energy and Enzymes – An Introduction to Metabolism

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