Q: Which equation correctly represents the hydrolysis of ATP and its associated free energy change?

$$\mathrm{ATP} + \mathrm{H}_2\mathrm{O} \rightarrow \mathrm{ADP} + \mathrm{P}_i + \mathrm{H}^+ \quad \Delta G = -7.3\ \text{kcal/mol}$$

Q: Which of the following reactions is exergonic?

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\mathrm{O}_2 \rightarrow 6\mathrm{CO}_2 + 6\mathrm{H}_2\mathrm{O} \quad \Delta G = -686\ \text{kcal/mol}$$

Question 1

Which of the following statements best describes the role of ATP in cellular energy transfer?

Accepted Answer

ATP stores energy in the bonds between its phosphate groups, and releases energy when a phosphate is removed.

Question 2

Which equation correctly represents the hydrolysis of ATP and its associated free energy change?

Accepted Answer

$$\mathrm{ATP} + \mathrm{H}_2\mathrm{O} ightarrow \mathrm{ADP} + \mathrm{P}_i + \mathrm{H}^+ \quad \Delta G = -7.3\ 	ext{kcal/mol}$$

Question 3

Which process in metabolism is responsible for breaking down large molecules into smaller ones and releasing energy?

Accepted Answer

Catabolism

Question 4

Which of the following best explains why ATP is considered a 'high-energy' molecule?

Accepted Answer

ATP contains three phosphate groups with strong charge repulsion, making the bonds unstable and easy to break.

Question 5

Which of the following reactions is exergonic?

Accepted Answer

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\mathrm{O}_2 ightarrow 6\mathrm{CO}_2 + 6\mathrm{H}_2\mathrm{O} \quad \Delta G = -686\ 	ext{kcal/mol}$$

Question 6

Which metabolic pathway is cyclic and regenerates its starting material?

Accepted Answer

Citric acid cycle

Question 7

What is the common molecule produced from the breakdown of carbohydrates, fats, and proteins before entering the citric acid cycle?

Accepted Answer

Acetyl Coenzyme A (acetyl-SCoA)

Question 8

Which vitamin is required for the synthesis of Coenzyme A?

Accepted Answer

Pantothenic acid

Question 9

During the citric acid cycle, which molecules are reduced as a result of substrate oxidation?

Accepted Answer

NAD+ and FAD

Question 10

Which step in the citric acid cycle produces an energy-carrying molecule similar to ATP?

Accepted Answer

Conversion of succinyl-SCoA to succinate produces GTP.

Question 11

Which of the following best describes oxidative phosphorylation?

Accepted Answer

The synthesis of ATP from ADP using energy released in the electron-transport chain.

Question 12

How many ATP molecules are produced from one NADH molecule during the electron transport chain?

Accepted Answer

3 ATP

Question 13

Which enzyme complex in the electron transport chain is responsible for synthesizing ATP as H+ ions flow back into the mitochondrial matrix?

Accepted Answer

ATP synthase

Question 14

Which of the following is a harmful by-product of the electron transport chain that can damage cell membranes and DNA?

Accepted Answer

Reactive oxygen species (ROS)

Question 15

Which antioxidant is responsible for protecting cell membranes from damage by free radicals?

Accepted Answer

Vitamin E (tocopherol)

Question 16

Which of the following best describes the coupling of chemical reactions in metabolism?

Accepted Answer

An endergonic reaction is paired with an exergonic reaction, and the energy released by the exergonic reaction powers the endergonic one.

Question 17

Which coenzyme is synthesized from the vitamin riboflavin?

Accepted Answer

FAD

Question 18

Which of the following is NOT a characteristic of oxidation reactions in biochemistry?

Accepted Answer

Gain of electrons

Question 19

Which enzyme acts as an allosteric activator for isocitrate dehydrogenase in the citric acid cycle when cellular energy is low?

Accepted Answer

ADP

Question 20

Which of the following is a real-life consequence of lacking superoxide dismutase or catalase enzymes?

Accepted Answer

Death in an oxygen atmosphere due to inability to eliminate excess ROS.

Biochemical Energy and the Generation of ATP

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