For each mole of glucose (C6H12O6) oxidized by cellular respiration, how many moles of CO2 are released in the citric acid cycle (see Figure 7.1)?
A) 2
B) 4
C) 6
D) 12
E) 3

Question

Quizplus · Accepted Answer

In the citric acid cycle, each mole of glucose is fully oxidized, leading to the release of 6 moles of CO2. However, the citric acid cycle only oxidizes half a glucose molecule, leading to the release of 3 moles of CO2. Since one mole of glucose leads to the oxidation of two molecules of pyruvate, which in turn enter the citric acid cycle, the total number of moles of CO2 released in the citric acid cycle is 6 (3 moles of CO2 per pyruvate molecule, times 2 pyruvate molecules per glucose molecule). Therefore, the correct answer is B, 4 moles of CO2 per mole of glucose oxidized.

For Each Mole of Glucose (C6H12O6) Oxidized by Cellular Respiration