Question: The Krebs cycle forms many products. Which option lists the correct products of the Krebs cycle after 1 molecule of glucose goes through it?

Answers:

net 1 NADH, 1 ATP, 2 CO₂, 1 FADH₂

6 NADH, 2 ATP, 4 CO₂, and 2 FADH₂

net 4 NADH, 4 ATP, 8 CO₂, 4 FADH₂

net 2 NAD⁺, 2 ATP, 4 CO₂, 2 FADH

1 answer

The correct option that lists the products of the Krebs cycle after 1 molecule of glucose goes through it is:

net 6 NADH, 2 ATP, 4 CO₂, and 2 FADH₂

Here's a brief explanation:

When one molecule of glucose undergoes glycolysis, it is converted into two molecules of pyruvate, which then enter the Krebs cycle (citric acid cycle) after being transformed into Acetyl-CoA. Each Acetyl-CoA that enters the cycle results in the production of:

3 NADH
1 FADH₂
1 ATP (or GTP)
2 CO₂

Since one glucose molecule generates two Acetyl-CoA molecules, the total yield from the Krebs cycle after processing both of them is:

6 NADH (3 NADH per Acetyl-CoA x 2)
2 ATP (1 ATP per Acetyl-CoA x 2)
4 CO₂ (2 CO₂ per Acetyl-CoA x 2)
2 FADH₂ (1 FADH₂ per Acetyl-CoA x 2)

So the first option is incorrect, the third is incorrect because the numbers don't add up, and the fourth option is not applicable as it mentions NAD⁺ instead of NADH.