Q: What is the net reaction and free energy change ($$\Delta G) $$for the coupled reaction of glucose phosphorylation by ATP?

$$\text{Glucose} + \text{ATP} \rightarrow \text{Glucose-6-phosphate} + \text{H}_2\text{O};\ \Delta G = -4.0\ \text{kcal/mol}$$

Q: Which of the following reactions is an example of oxidation?

$$\text{CH}_3\text{CH}_2\text{OH} \rightarrow \text{CH}_3\text{CHO}$$

Q: Which of the following is the correct net equation for the citric acid cycle for one acetyl-CoA molecule?

$$\text{Acetyl-CoA} + 3\text{NAD}^+ + \text{FAD} + \text{GDP} + \text{HOPO}_3$$^{2-}$$ + \text{H}_2\text{O} \rightarrow \text{HSCoA} + 3\text{NADH} + 3\text{H}^+ + \text{FADH}_2 + \text{GTP} + 2\text{CO}_2$$

Question 1

Which of the following best describes the difference between catabolism and anabolism in cellular metabolism?

Accepted Answer

Catabolism breaks down large molecules into smaller ones, releasing energy, while anabolism synthesizes large molecules from smaller ones, absorbing energy.

Question 2

Which of the following is a characteristic of a cyclic metabolic pathway?

Accepted Answer

It regenerates the first reactant in the series of reactions.

Question 3

Where in the cell does the majority of ATP production occur?

Accepted Answer

Mitochondrial matrix

Question 4

Which molecule acts as a common intermediate in the breakdown of carbohydrates, proteins, and lipids?

Accepted Answer

Acetyl-CoA

Question 5

What is the net reaction and free energy change ($$\Delta G) $$for the coupled reaction of glucose phosphorylation by ATP?

Accepted Answer

$$	ext{Glucose} + 	ext{ATP} ightarrow 	ext{Glucose-6-phosphate} + 	ext{H}_2	ext{O};\ \Delta G = -4.0\ 	ext{kcal/mol}$$

Question 6

Which coenzyme is reduced during the oxidation of malate to oxaloacetate in the citric acid cycle?

Accepted Answer

NAD+

Question 7

What is the main function of the citric acid cycle?

Accepted Answer

To generate reduced coenzymes (NADH and FADH2) for ATP production

Question 8

Which enzyme catalyzes the conversion of citrate to isocitrate in the citric acid cycle, and what type of reaction is this?

Accepted Answer

Aconitase; isomerization

Question 9

How many ATP molecules are produced from the oxidation of one NADH molecule in the electron transport chain?

Accepted Answer

2.5 ATP

Question 10

Which of the following statements about oxidative phosphorylation is correct?

Accepted Answer

It uses the energy from reduced coenzymes to synthesize ATP.

Question 11

During which stage of metabolism are fatty acids converted to acetyl-CoA?

Accepted Answer

Stage 2: Acetyl-CoA production

Question 12

Which of the following best describes the role of ATP synthase in the mitochondria?

Accepted Answer

It catalyzes the phosphorylation of ADP to ATP using the energy from the proton gradient.

Question 13

Which of the following reactions is an example of oxidation?

Accepted Answer

$$	ext{CH}_3	ext{CH}_2	ext{OH} ightarrow 	ext{CH}_3	ext{CHO}$$

Question 14

If a mutation caused the inhibition of complex IV in the electron transport chain, what would be the most immediate effect?

Accepted Answer

Oxygen consumption would decrease.

Question 15

Which of the following is the correct net equation for the citric acid cycle for one acetyl-CoA molecule?

Accepted Answer

$$	ext{Acetyl-CoA} + 3	ext{NAD}^+ + 	ext{FAD} + 	ext{GDP} + 	ext{HOPO}_3$$^{2-}$$ + 	ext{H}_2	ext{O} ightarrow 	ext{HSCoA} + 3	ext{NADH} + 3	ext{H}^+ + 	ext{FADH}_2 + 	ext{GTP} + 2	ext{CO}_2$$

Question 16

Which of the following statements about the entry of electrons into the electron transport chain is correct?

Accepted Answer

NADH donates electrons at complex I, while FADH2 donates at complex II.

Question 17

A patient is diagnosed with a genetic disorder that prevents the conversion of succinate to fumarate. Which coenzyme would be directly affected in its reduced form?

Accepted Answer

FADH2

Question 18

Which of the following best explains why the electron transport chain is considered aerobic?

Accepted Answer

Oxygen acts as the final electron acceptor, forming water.

Question 19

If the proton gradient across the inner mitochondrial membrane is dissipated (for example, by a chemical uncoupler), what is the most likely consequence?

Accepted Answer

ATP synthesis by ATP synthase would decrease.

Metabolism and Energy Production in Organic Chemistry

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