Figure 9.2 The citric acid cycle.
-For each mole of glucose (C₆H₁₂O₆)oxidized by cellular respiration, how many moles of CO₂ are released in the citric acid cycle (see Figure 9.2)?
A) 2
B) 4
C) 6
D) 12
E) 3

Question

Figure 9.2 The citric acid cycle.
-For each mole of glucose (C₆H₁₂O₆)oxidized by cellular respiration, how many moles of CO₂ are released in the citric acid cycle (see Figure 9.2)?
A) 2 
B) 4 
C) 6 
D) 12 
E) 3

Quizplus · Accepted Answer

In the citric acid cycle, each mole of glucose yields 2 moles of pyruvate which enters into the cycle. During the cycle, two carbons from each pyruvate molecule are released as CO₂. As two molecules of pyruvate are formed from one molecule of glucose, a total of 4 moles of CO₂ are released in the citric acid cycle. Therefore, the best choice is B.

Figure 9.2 the Citric Acid Cycle