Question

Select ALL of the statements that correctly describe the Krebs cycle.

A.

Pyruvic acid must be converted to acetyl CoA prior to entering the cycle

B.

The molecule oxaloacetic acid picks up the acetyl group from acetylCoA, and in the last step of the cycle, oxaloacetic acid is regenerated.

C.

Electrons removed during oxidation steps are picked up by NAD or FAD.

D.

Each turn of the cycle generates one ATP molecule for a total of two per molecule of glucose.

E.

Most of the ATP generated during the aerobic respiration of glucose is generated during the Krebs cycle.

F.

Carbon dioxide is released at two different steps in the cycle.

2. Select ALL the TRUE statements regarding glycolysis

A.	Glycolysis produces 32-34 molecules of ATP per glucose molecule

B.	Glycolysis occurs within the mitochondrial matrix of both prokaryotes and eukaryotes.
	C.	During the conversion stages of 3-carbon molecules that result in forming pyruvic acid (pyruvate), NAD+ is reduced to NADH.
	D.	The pyruvate made during glycolysis can be used either in the Krebs cycle or fermentation, and the NADH+ is used in the electron transport chain.
	E.	Two molecules of ATP are utilized to fuel the reactions of glycolysis.
	F.	Glycolysis is the breakdown of glucose, which is a key part of the metabolism of both aerobic and anaerobic organisms.

Answer 1

Correct answer

1A. Pyruvic acid must be converted to acetyl CoA prior to entering the cycle

1B. The molecule oxaloacetic acid picks up the acetyl group from acetylCoA, and in the last step of the cycle, oxaloacetic acid is regenerated.

1C. Electrons removed during oxidation steps are picked up by O₂.

1D. Each turn of the cycle generates two ATP molecule for a total of one per molecule of glucose.

1E. Most of the ATP generated during the aerobic respiration of glucose is generated during the oxidative phosphorylation.

1F. Carbon dioxide is released at two different steps in the cycle.

2A. Glycolysis produces 2 molecules of ATP per glucose molecule.

2B. Glycolysis occurs in cytosol of both prokaryotes and eukaryotes.

2C. During the conversion stages of 3-carbon molecules that result in forming pyruvic acid (pyruvate), NAD+ is reduced to NADH.

2D. The pyruvate made during glycolysis can be used either in the Krebs cycle or fermentation, and the NADH is used in the electron transport chain.

2E. Two molecules of ATP are utilized to fuel the reactions of glycolysis.

2F. Glycolysis is the breakdown of glucose, which is a key part of the metabolism of both aerobic and anaerobic organisms.