Question 1

Which of the following best describes metabolism in living organisms?

Accepted Answer

The sum of all chemical reactions occurring within a cell or organism.

Question 2

Which of the following is an example of a catabolic pathway?

Accepted Answer

Hydrolysis of glycogen to glucose monomers.

Question 3

Bioenergetics is best defined as:

Accepted Answer

The study of how organisms manage their energy resources.

Question 4

Which of the following statements about the first law of thermodynamics is correct?

Accepted Answer

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

Question 5

A reaction has $$\Delta G = -5$$ kcal/mol. Which of the following is true about this reaction?

Accepted Answer

It is exergonic and will occur spontaneously.

Question 6

Which of the following best explains why cells must remain in an open system?

Accepted Answer

To prevent metabolic reactions from reaching equilibrium and stopping cellular work.

Question 7

ATP hydrolysis releases energy because:

Accepted Answer

The repulsion between negatively charged phosphate groups is relieved.

Question 8

Which equation correctly represents the free energy change for a reaction?

Accepted Answer

$$\Delta G = \Delta H - T\Delta S$$

Question 9

Which of the following is NOT a way that enzymes lower the activation energy of a reaction?

Accepted Answer

Increasing the temperature of the cell.

Question 10

A competitive inhibitor decreases the rate of an enzyme-catalyzed reaction by:

Accepted Answer

Binding to the active site and blocking substrate binding.

Question 11

Which of the following best describes feedback inhibition?

Accepted Answer

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

Question 12

Which of the following is an example of an anabolic pathway?

Accepted Answer

Synthesis of proteins from amino acids.

Question 13

Which of the following statements about enzyme specificity is correct?

Accepted Answer

Enzymes have specific shapes that allow them to bind only certain substrates.

Question 14

Which of the following is a coenzyme?

Accepted Answer

NAD$$^+$$ derived from niacin (vitamin B3).

Question 15

If the optimal temperature for a human enzyme is 37°C, what is most likely to happen at 70°C?

Accepted Answer

The enzyme will denature and lose its catalytic activity.

Question 16

Which of the following is true about the ATP cycle in cells?

Accepted Answer

ATP is continuously regenerated from ADP and $$P_i$$ using energy from catabolic reactions.

Question 17

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

Accepted Answer

They lower the activation energy barrier, increasing the rate of reaction.

Question 18

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

Accepted Answer

Exergonic reactions have $$\Delta G  0$$ and require energy input.

Question 19

Which of the following is NOT a function of ATP in the cell?

Accepted Answer

Acting as a catalyst for chemical reactions.

Question 20

A noncompetitive inhibitor decreases enzyme activity by:

Accepted Answer

Binding to a site other than the active site and changing the enzyme's shape.

Chapter 8: Introduction to Metabolism – Study Notes

Study Guide - Practice Questions