When there is a available oxygen in the environment, how many ATP molecules can the ETP produce from a glucose molecule?

38

36

32

6

One molecule of Glucose produces 38 molecules of ATP through the ETC in presence of enough oxygen.

Explanation:

To know the number of ATP produced from a molecule of glucose, we need to know the total amount and the type of products produced in the 3 individual steps of an aerobic respiration.

1. Glycolisis - In glycolisis, one molecule of glucose is converted into two molecules of pyruvate with production of 2 ATP molecules and 2 molecules of NADH.

2. Pyruvate Dehydroogenase step - Two molecules of pyruvate produce a total of 2 NADH.

2. Kreb's Cycle - In Kreb's Cycle, two molecules of Acetyl CoA produce a total of 6 NADH, 2FADH and 2 GTP which is again equivalent to 2 ATP.

In the ETC, each NADH is converted into 3 molecules of ATP and each FADH is converted into 2 molecules of ATP.

In the whole process till now, total of 10 molecules of NADH, 2 molecules of FADH and 4 ATPs.

So total number of ATP produced is 10*3 + 2*2 + 4 = 30+4+4 = 38.