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

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

Q: Which of the following reactions is an example of substrate-level phosphorylation?

$$\mathrm{1,3\text{-}bisphosphoglycerate} + \mathrm{ADP} \rightarrow \mathrm{3\text{-}phosphoglycerate} + \mathrm{ATP}$$

Question 1

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

Accepted Answer

ATP acts as a universal energy coupler, transferring energy from catabolic to anabolic reactions.

Question 2

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

Accepted Answer

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

Question 3

During glycolysis, which step is responsible for the generation of NADH?

Accepted Answer

The oxidation of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate (Gly-6).

Question 4

Which of the following statements about fermentation is correct?

Accepted Answer

Fermentation regenerates NAD+ from NADH, allowing glycolysis to continue in the absence of oxygen.

Question 5

Which of the following is a key regulatory enzyme unique to glycolysis?

Accepted Answer

Phosphofructokinase-1 (PFK-1)

Question 6

What is the net yield of ATP and NADH per molecule of glucose during glycolysis?

Accepted Answer

2 ATP and 2 NADH

Question 7

Which of the following best explains why ATP is considered an intermediate in terms of bond energy?

Accepted Answer

ATP can both donate and accept phosphate groups because its free energy of hydrolysis is intermediate compared to other phosphorylated compounds.

Question 8

Which of the following reactions is an example of substrate-level phosphorylation?

Accepted Answer

$$\mathrm{1,3	ext{-}bisphosphoglycerate} + \mathrm{ADP} ightarrow \mathrm{3	ext{-}phosphoglycerate} + \mathrm{ATP}$$

Question 9

Which molecule acts as the primary electron acceptor during glycolysis?

Accepted Answer

NAD+

Question 10

Which of the following best describes the difference between anabolic and catabolic pathways?

Accepted Answer

Anabolic pathways build complex molecules from simpler ones and require energy, while catabolic pathways break down complex molecules and release energy.

Question 11

Which of the following statements about gluconeogenesis is correct?

Accepted Answer

Gluconeogenesis bypasses the three most exergonic reactions of glycolysis using alternative enzymes and energy input from ATP and GTP.

Question 12

Which compound is the end product of glycolysis under anaerobic conditions in yeast?

Accepted Answer

Ethanol

Question 13

Which of the following is a correct summary equation for glycolysis?

Accepted Answer

$$\mathrm{glucose} + 2\mathrm{NAD}^+ + 2\mathrm{ADP} + 2\mathrm{P}_i \rightarrow 2\mathrm{pyruvate} + 2\mathrm{NADH} + 2\mathrm{H}^+ + 2\mathrm{ATP}$$

Question 14

Which enzyme catalyzes the conversion of phosphoenolpyruvate (PEP) to pyruvate in glycolysis?

Accepted Answer

Pyruvate kinase

Question 15

Which of the following best describes the regulation of glycolysis and gluconeogenesis?

Accepted Answer

They are reciprocally regulated by key intermediates such as AMP and acetyl CoA, which have opposite effects on each pathway.

Question 16

Which of the following statements about NAD+ is correct?

Accepted Answer

NAD+ serves as an electron acceptor in biological oxidation reactions, forming NADH.

Question 17

Which of the following is a plausible consequence of a mutation that inactivates phosphofructokinase-1 (PFK-1) in a liver cell?

Accepted Answer

Glycolysis would be severely impaired, leading to decreased ATP production from glucose.

Question 18

Which of the following best explains why glycolysis is highly exergonic in the direction of pyruvate formation?

Accepted Answer

The pathway includes several irreversible steps with large negative $$\Delta G$$ values, ensuring the overall reaction proceeds spontaneously.

Question 19

Which of the following is a real-world example of the importance of fermentation?

Accepted Answer

Yeast cells produce ethanol and CO2 during fermentation, which is essential for bread making and alcoholic beverage production.

Ch 9 - Chemotropic Energy Metabolism: Glycolysis and Fermentation

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