Question

If you were to add one of the eight citric acid cycle intermediates to the culture medium of yeast growing in the laboratory, what do you think would happen to the rates of ATP and carbon dioxide production?
A) There would be no change in ATP production, but we would observe an increased rate of carbon dioxide production.
B) The rates of ATP production and carbon dioxide production would both increase.
C) The rate of ATP production would decrease, but the rate of carbon dioxide production would increase.
D) Rates of ATP and carbon dioxide production would probably both decrease.

Answer 1

Answer:

B) The rates of ATP production and carbon dioxide production would both increase.

Explanation:

The citric acid cycle is the second stage of aerobic cellular respiration. It includes complete oxidation of acetyl CoA into CO2 and H2O. During the citric acid cycle, NAD and FAD serve as electron acceptors. Reduction of these reducing powers forms NADH and FADH2 which in turn enter the electron transport chain for their oxidation and drive the process of as many as 32 ATP molecules by oxidative phosphorylation. On the other hand, fermentation forms of 2 ATP molecules and a few or no CO2 molecules.

Therefore, if one of the eight intermediates of the citric acid cycle is added to the medium, the yeast cells would perform aerobic cellular respiration and would form more CO2 and ATP molecules than the ones formed during the process of fermentation.