Q: Which of the following equations correctly represents the standard free energy change for ATP hydrolysis?

$$\Delta G$$^{\circ\prime}$$ = -7.3\ \text{kcal/mol}$$

Q: Which of the following is the correct overall equation for the aerobic oxidation of glucose?

$$\mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$} \rightarrow 6\mathrm{CO_2$} + 6\mathrm{H_2O} + \text{Energy (ATP and heat)}$$

Question 1

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

Accepted Answer

Catabolism increases entropy and is exergonic, while anabolism decreases entropy and is endergonic.

Question 2

Which of the following bonds in ATP is responsible for the largest release of free energy upon hydrolysis?

Accepted Answer

The phosphoanhydride bond between the terminal two phosphates

Question 3

Why is ATP hydrolysis considered highly exergonic? Select the most complete explanation.

Accepted Answer

Because the products of hydrolysis are more stabilized by resonance, have increased entropy, and experience less charge repulsion.

Question 4

Which of the following equations correctly represents the standard free energy change for ATP hydrolysis?

Accepted Answer

$$\Delta G$$^{\circ\prime}$$ = -7.3\ 	ext{kcal/mol}$$

Question 5

Which of the following statements about NAD+ is TRUE?

Accepted Answer

NAD+ is reduced to NADH by accepting two electrons and one proton.

Question 6

Which of the following best describes substrate-level phosphorylation during glycolysis?

Accepted Answer

ATP is generated directly by transferring a phosphate group from a high-energy substrate to ADP.

Question 7

A facultative anaerobe is an organism that:

Accepted Answer

Can survive with or without oxygen, but prefers aerobic conditions.

Question 8

Which enzyme catalyzes the phosphorylation of glucose to glucose-6-phosphate in glycolysis, and why is this step considered irreversible?

Accepted Answer

Hexokinase; because the reaction is highly exergonic ($$\Delta G$$^{\circ\prime}$$ \u003c 0) $$and coupled to ATP hydrolysis.

Question 9

During glycolysis, what is the net gain of ATP and NADH per molecule of glucose?

Accepted Answer

2 ATP and 2 NADH

Question 10

Which of the following best explains why the hydrolysis of phosphoanhydride bonds in ATP releases more energy than the hydrolysis of phosphoester bonds?

Accepted Answer

Phosphoanhydride bonds are less stable due to greater charge repulsion and both products are resonance stabilized.

Question 11

Which of the following is the correct overall equation for the aerobic oxidation of glucose?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$} ightarrow 6\mathrm{CO_2$} + 6\mathrm{H_2O} + 	ext{Energy (ATP and heat)}$$

Question 12

Which of the following is NOT a reason why ATP hydrolysis is exergonic?

Accepted Answer

Decrease in entropy

Question 13

In a patient with a genetic defect in phosphofructokinase-1, which step of glycolysis would be directly affected?

Accepted Answer

Conversion of fructose-6-phosphate to fructose-1,6-bisphosphate

Question 14

Which of the following best describes the fate of NADH produced during glycolysis under aerobic conditions?

Accepted Answer

It donates electrons to the electron transport chain in the mitochondria.

Question 15

Which of the following statements about glycolysis is FALSE?

Accepted Answer

Glycolysis directly produces carbon dioxide as a byproduct.

Question 16

Which of the following best explains why glucose is phosphorylated in the first step of glycolysis?

Accepted Answer

To trap glucose inside the cell and destabilize it for further breakdown

Question 17

Which of the following is a correct description of oxidation in biological systems?

Accepted Answer

Oxidation is the loss of electrons and hydrogen atoms.

Question 18

If a cell is exposed to a toxin that inhibits the enzyme hexokinase, what would be the immediate effect on glycolysis?

Accepted Answer

Glycolysis would stop at the first step, preventing glucose from being phosphorylated.

Question 19

Which of the following best describes the role of ATP in linking catabolic and anabolic pathways?

Accepted Answer

ATP acts as an energy currency, storing energy from catabolism and providing it for anabolism.

Chemotropic Energy Metabolism: Glycolysis and ATP in Cellular Bioenergetics

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