If you take into account the amount of ATP generated by ATP synthase per molecule of NADH and per molecule of FADH₂ produced,and the number of ATP molecules produced by substrate-level phosphorylation,what is the predicted energy yield of the Citric acid cycle,per molecule of glucose in eukaryotic cells?

Question

Quizplus · Accepted Answer

The predicted energy yield of the citric acid cycle, per molecule of glucose in eukaryotic cells is 20 ATP.

- For each molecule of glucose, glycolysis generates 2 ATP and 2 NADH. 
- Each NADH molecule produced in glycolysis enters the electron transport chain (ETC), where it generates 2.5 ATP. So, the 2 NADH generated in glycolysis produce a total of 5 ATP. 
- In addition, the Krebs cycle (citric acid cycle) generates 2 ATP, 6 NADH, and 2 FADH2 per molecule of glucose. 
- Each NADH molecule that enters the ETC from the citric acid cycle generates 2.5 ATP, while each FADH2 molecule generates 1.5 ATP. So, the 6 NADH and 2 FADH2 molecules produced by the citric acid cycle produce a total of 17 ATP. 
- Finally, 2 ATP are produced by substrate-level phosphorylation in the Krebs cycle.

Adding up all of the ATP produced by glycolysis, the citric acid cycle, and the ETC, we get a total of:

2 + 5 + 17 + 2 = 26 ATP

However, 2 ATP are consumed during glycolysis, leaving us with a net gain of:

26 - 2 = 24 ATP

But since the question asks for the energy yield of the citric acid cycle specifically, we just need to consider the 2 ATP produced by substrate-level phosphorylation in the Krebs cycle, and the ATP produced by the NADH and FADH2 that enter the ETC from the citric acid cycle:

2 + (6 x 2.5) + (2 x 1.5) = 20 ATP

Therefore, the best choice is D, 20 ATP.

If You Take into Account the Amount of ATP Generated