In eukaryotes, you get a net of 36 ATP with oxidative phosphorylation (OP) producing 32 ATP. To understand why, you add up all sources of NADH and FADH2, along with ATP produced via substrate phosphorylation.
Substrate: 2 ATP during Glycolysis + 2 ATP during Krebs = 4 ATP
Oxidative:
6 NADH during Krebs + 2 during Acetyl CoA formation + 2 during glycolysis = 10 NADH
2 FADH2 during Krebs = 2 FADH2
In general 1 NADH yields 3 ATP, and 1 FADH2 yields 2 ATP. However, in eukaryotes the NADH produced during glycolysis in cytoplasm has to enter mitochondria via active transport, which takes up some energy, so the 2 NADH of glycolysis only give you a net of 2 ATP each. So, the total ATP by oxidative phosphorylation:
2 FADH2 X 2 ATP = 4 ATP
8 NADH X 3 ATP = 24 ATP
2 NADH X 2 ATP = 4 ATP
=
32 ATP using OP in eukaryotes
Total = 32 ATP + 4 ATP using substrate phosphorylation =
36 ATP
In prokaryotes, you get 38 ATP because there's no active transport required from cytoplasm to mitochondria as prokaryotes lack mitochondria.
Hope this helps.
Supposedly oxidative phosphorylation only produces a net of 32ATP? Can someone please explain why? If there is a net 32ATP from OP, then why isn't the overall ATP production of glucose breakdown 34 as opposed to 36? If someone could please explain it would be great. Thanks!