Question 1

Which of the following best describes the difference between kinetic energy and potential energy in biological systems?

Accepted Answer

Kinetic energy is the energy of motion, while potential energy is stored energy due to position or structure.

Question 2

During cellular respiration, which molecule acts as the final electron acceptor in the electron transport chain (ETC)?

Accepted Answer

O$$_2$$

Question 3

Which of the following statements about enzyme activity is correct?

Accepted Answer

Enzymes lower the activation energy ($$E_a) $$but do not change the overall free energy change ($$\Delta G) of $$the reaction.

Question 4

A biosynthetic reaction in a cell has a standard free-energy change ($$\Delta G^\circ') of$$ $$+5.6$$ kcal/mol, and the hydrolysis of ATP to ADP and Pi has a $$\Delta G^\circ' of$$ $$-7.3$$ kcal/mol. If these reactions are coupled, what is the overall $$\Delta G^\circ'$$?

Accepted Answer

$$-1.7$$ kcal/mol

Question 5

Which of the following best explains why high temperatures can decrease enzyme activity?

Accepted Answer

High temperatures denature the enzyme, altering its active site and preventing substrate binding.

Question 6

In glycolysis, what are the net products per molecule of glucose?

Accepted Answer

2 pyruvate, 2 ATP, 2 NADH

Question 7

Which process in cellular respiration directly produces the most ATP per glucose molecule?

Accepted Answer

Oxidative phosphorylation

Question 8

Which statement correctly describes the role of NAD$$^+ in $$cellular respiration?

Accepted Answer

NAD$$^+ is $$reduced to NADH, which then donates electrons to the electron transport chain.

Question 9

Which of the following is an example of feedback inhibition in metabolic pathways?

Accepted Answer

The end product of a pathway binds to an enzyme early in the pathway, decreasing its activity.

Question 10

During aerobic respiration, what is the main purpose of the proton gradient across the inner mitochondrial membrane?

Accepted Answer

To drive the synthesis of ATP via ATP synthase

Question 11

Which of the following best describes substrate-level phosphorylation?

Accepted Answer

The direct transfer of a phosphate group from an organic substrate to ADP to form ATP

Question 12

Which of the following is true about the difference between fermentation and aerobic respiration?

Accepted Answer

Aerobic respiration requires oxygen, while fermentation does not.

Question 13

Which of the following statements about competitive and noncompetitive enzyme inhibitors is correct?

Accepted Answer

Competitive inhibitors bind to the active site, while noncompetitive inhibitors bind to a different site on the enzyme.

Question 14

Which human enzyme functions well at pH 2 and where is it found?

Accepted Answer

Pepsin; stomach

Question 15

What is the role of ATP in cellular metabolism?

Accepted Answer

ATP acts as a universal energy currency, coupling exergonic and endergonic reactions.

Question 16

Which of the following is true regarding the products of glucose oxidation in cellular respiration?

Accepted Answer

CO$$_2$$, H$$_2O$$, and ATP are produced.

Question 17

Which stage of cellular respiration occurs in the cytoplasm?

Accepted Answer

Glycolysis

Question 18

If oxygen is not available, which process allows cells to continue producing ATP via glycolysis?

Accepted Answer

Fermentation

Question 19

Which of the following is regenerated during fermentation to allow glycolysis to continue?

Accepted Answer

NAD$$^+$$

Question 20

Which of the following best describes the difference between oxidation and reduction in cellular respiration?

Accepted Answer

Oxidation is the loss of electrons, reduction is the gain of electrons.

General Biology Study Guide: Energy, Metabolism, Enzymes, and Cellular Respiration

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