Question 1

Which of the following best describes the role of enzymes in metabolic pathways?

Accepted Answer

Enzymes lower the activation energy and speed up reactions without being consumed.

Question 2

A diver standing on a platform has more potential energy than when in the water. Which equation best represents the conversion of this energy as the diver jumps?

Accepted Answer

$$E_{potential} \rightarrow E_{kinetic}$$

Question 3

Which statement about the first law of thermodynamics is correct?

Accepted Answer

Energy can be transferred or transformed, but cannot be created or destroyed.

Question 4

In the ATP cycle, what is the significance of phosphorylation?

Accepted Answer

It transfers a phosphate group to another molecule, increasing its reactivity.

Question 5

Which of the following is an example of an exergonic reaction?

Accepted Answer

Hydrolysis of ATP to ADP and $$P_i$$

Question 6

A cheetah uses the chemical energy in its food to run. According to the second law of thermodynamics, what happens to some of this energy?

Accepted Answer

Some energy is lost as heat during the transformation.

Question 7

Which equation correctly represents the hydrolysis of ATP?

Accepted Answer

$$ATP + H_2O \rightarrow ADP + P_i + energy$$

Question 8

Which environmental factor is most likely to affect enzyme activity in the human stomach?

Accepted Answer

Low pH (around 2)

Question 9

What is the main difference between exergonic and endergonic reactions?

Accepted Answer

Exergonic reactions release energy, while endergonic reactions require energy input.

Question 10

Which of the following best describes feedback inhibition in metabolic pathways?

Accepted Answer

The end product of a pathway inhibits an earlier enzyme, preventing overproduction.

Question 11

Which scenario illustrates coupling of exergonic and endergonic reactions in cells?

Accepted Answer

ATP hydrolysis releases energy that is used to drive the synthesis of glutamine from glutamic acid and ammonia.

Question 12

Which of the following statements about the induced fit hypothesis is correct?

Accepted Answer

Enzymes slightly change shape at the active site to enhance substrate binding and catalytic ability.

Question 13

A metabolic pathway is regulated by feedback inhibition. What would happen if the end product is removed from the system?

Accepted Answer

The pathway would speed up as inhibition is relieved.

Question 14

Which of the following is NOT a type of work powered by ATP in cells?

Accepted Answer

Thermal work

Question 15

Which of the following best explains why enzymes are considered catalysts?

Accepted Answer

They speed up reactions by lowering the activation energy without being changed themselves.

Question 16

Which equation represents the change in free energy ($$\Delta G) $$for an exergonic reaction?

Accepted Answer

$$\Delta G \u003c 0$$

Question 17

Which factor is most likely to denature an enzyme and stop its activity?

Accepted Answer

Extreme pH

Question 18

Which of the following is a real-life example of kinetic energy?

Accepted Answer

Water flowing out of a faucet

Question 19

Which statement best describes the relationship between chemical energy and cellular work?

Accepted Answer

Chemical energy stored in molecules is released during reactions to power cellular work.

Question 20

Which of the following is true about the enzyme-substrate complex?

Accepted Answer

It is formed when the substrate binds to the enzyme's active site.

Metabolism: Energy, Enzymes, and Cellular Work

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