If glucose is the sole energy source, what fraction of the carbon dioxide exhaled by animals is generated only by the reactions involved in oxidation of pyruvate to acetyl CoA?
A) 1/6
B) 1/3
C) 2/3
D) all of it

Question

Quizplus · Accepted Answer

When glucose is metabolized, it is first converted to pyruvate via glycolysis. Each pyruvate molecule is then converted to acetyl CoA, releasing one molecule of CO2. Since one glucose molecule produces two pyruvate molecules, two CO2 molecules are released at this stage. In total, complete oxidation of one glucose molecule produces six CO2 molecules (two from pyruvate to acetyl CoA and four from the citric acid cycle), so 1/3 of the CO2 comes from the conversion of pyruvate to acetyl CoA.

If Glucose Is the Sole Energy Source, What Fraction of the Carbon