Question 1

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

Accepted Answer

Catabolic pathways release energy by breaking down complex molecules, and anabolic pathways use that energy to build complex molecules.

Question 2

According to the first law of thermodynamics, which of the following statements is correct?

Accepted Answer

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

Question 3

A tiger swimming underwater is an example of which type of energy transformation?

Accepted Answer

Potential energy to kinetic energy

Question 4

Which of the following reactions is most likely to be spontaneous?

Accepted Answer

A catabolic reaction with $$\Delta G \u003c 0$$

Question 5

What is the primary role of ATP in cellular metabolism?

Accepted Answer

To serve as an energy shuttle, transferring energy from exergonic to endergonic reactions

Question 6

Which of the following best explains why the hydrolysis of ATP releases energy?

Accepted Answer

The bond between the phosphate groups is weak due to repelling negative charges, and breaking it releases energy.

Question 7

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy ($$E_A) of a $$reaction without affecting $$\Delta G.$$

Question 8

A cell is exposed to a chemical that lowers its cytoplasmic pH from 7.2 to 4.0. What is the most likely effect on cytoplasmic enzymes?

Accepted Answer

Enzymes would probably denature and enzymatic activity would decline.

Question 9

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

Accepted Answer

Increasing the $$\Delta G of $$the reaction

Question 10

A competitive inhibitor affects an enzyme by:

Accepted Answer

Binding to the active site and blocking substrate binding

Question 11

Which of the following best describes feedback inhibition in a metabolic pathway?

Accepted Answer

The end product of the pathway inhibits an enzyme that acts early in the pathway.

Question 12

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

Accepted Answer

Using the energy released from ATP hydrolysis to drive an endergonic reaction

Question 13

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

Accepted Answer

ATP consists of adenine, ribose, and three phosphate groups.

Question 14

Which of the following best explains why cells are considered open systems?

Accepted Answer

They exchange both energy and matter with their surroundings.

Question 15

Apoenzyme refers to:

Accepted Answer

The protein portion of an enzyme, without its cofactor

Question 16

Which of the following is a correct statement about allosteric regulation of enzymes?

Accepted Answer

Allosteric regulation involves binding of molecules at sites other than the active site, which can inhibit or activate the enzyme.

Question 17

Which of the following best describes the effect of temperature on enzyme activity?

Accepted Answer

Enzyme activity increases with temperature up to an optimal point, then decreases as the enzyme denatures.

Question 18

Which of the following is true about the second law of thermodynamics as it applies to biological systems?

Accepted Answer

Every energy transfer increases the entropy (disorder) of the universe.

Question 19

Which of the following is a real-life example of an anabolic process?

Accepted Answer

Synthesis of proteins from amino acids during muscle growth

Question 20

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

Accepted Answer

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

An Introduction to Metabolism: Cellular Energy and Enzyme Function

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