Question 1

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

Accepted Answer

ATP provides energy for cellular functions by coupling exergonic and endergonic reactions.

Question 2

A reaction has a change in free energy $$\Delta G = -15\ \mathrm{kJ/mol}. $$What does this indicate about the reaction?

Accepted Answer

The reaction is exergonic and will proceed spontaneously.

Question 3

Which statement about metabolic pathways is correct?

Accepted Answer

Metabolic pathways consist of multiple steps, each catalyzed by a specific enzyme.

Question 4

What is the primary difference between catabolic and anabolic pathways?

Accepted Answer

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

Question 5

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

Accepted Answer

Cells constantly exchange materials and energy with their environment, preventing equilibrium.

Question 6

A proton pump uses active transport to move hydrogen ions against their concentration gradient. Is this process exergonic or endergonic, and what is the sign of $$\Delta G$$?

Accepted Answer

Endergonic; $$\Delta G \u003e 0$$

Question 7

Which of the following is true about enzyme function?

Accepted Answer

Enzymes lower the activation energy barrier, speeding up reactions.

Question 8

If a competitive inhibitor is present, what effect does it have on enzyme activity?

Accepted Answer

It binds to the enzyme's active site, preventing substrate binding.

Question 9

Which of the following is an example of potential energy in a biological system?

Accepted Answer

Energy stored in the chemical bonds of glucose.

Question 10

Why is it important that metabolic reactions in cells do not reach equilibrium?

Accepted Answer

If metabolic reactions reached equilibrium, cells would not be able to do work and would die.

Question 11

Which of the following best describes energy coupling in cells?

Accepted Answer

Using the energy released from exergonic reactions to drive endergonic reactions.

Question 12

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

Accepted Answer

$$\Delta G = G_{products} - G_{reactants}$$

Question 13

Which of the following would most likely increase the rate of an enzyme-catalyzed reaction?

Accepted Answer

Adding more substrate when the enzyme is not saturated.

Question 14

A cell needs to synthesize a large macromolecule. Which type of metabolic pathway will it use, and what is the energy requirement?

Accepted Answer

Anabolic pathway; consumes energy

Question 15

Which of the following statements about cofactors is correct?

Accepted Answer

Cofactors are non-protein helpers that assist enzyme function.

Question 16

Which scenario best illustrates the concept of kinetic energy in a cell?

Accepted Answer

Movement of motor proteins along microtubules during cell division.

Question 17

Which of the following is NOT a function of enzymes in biological systems?

Accepted Answer

Being consumed and permanently altered during reactions.

Question 18

A noncompetitive inhibitor affects enzyme activity by:

Accepted Answer

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

Question 19

Which of the following best explains why ATP must be continuously regenerated in cells?

Accepted Answer

ATP is unstable and cannot be stored for long periods.

Question 20

Which of the following would most likely decrease the effectiveness of an enzyme?

Accepted Answer

Adding a competitive inhibitor.

Chapter 6: An Introduction to Metabolism and Cellular Bioenergetics

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