1 About 32 or some other number depending on where you are r

1. About 32 (or some other number, depending on where you are reading) molecules of ATP could potentially be made in respiration for each molecule of glucose. Explain one reason that we don’t actually make that many or why we can’t give an exact number.

Solution

2ATP,

2NADH(20 H⁺ - >5ATP)

2ATP

3-5 ATP

2ATP/GTP

6NADH (60H⁺ -> 15ATP)

2 FADH₂ (12H⁺ -> 3ATP)

2ATP

15 ATP

3 ATP

The yield from Glycolysis isn’t exact, it can be either 3 or 5. This is because Glycolysis occurs in the cytosol and NADH can’t pass through the membrane into the mitochondria. Because it can’t deliver the electrons to complex 1, it needs an intermediary, a shuttle system.

Some cells hand it over to FADH2 inside the inner mitochondrial membrane, this results in 3 ATP (2 NADH -> 2FADH2 -> 12 H+ -> 3 ATP). Other cells use NADH inside the inner mitochondrial membrane, resulting in 5 ATP (2 NADH -> 2NADH -> 20 H+ -> 5 ATP). 30-32 ATP is the upper bound of the estimate, in reality it is probably lower. This is the entire process where glucose is turned into energy that a cell can use.