From the oxidation of one molecule of palmitic acid ,the number of ATP molecules gained are ? (Give a detailed calculation)

Theoretically ATP yield for every oxidation cycle can be maximum upto 17, as NADH produces 3 ATP, FADH2 = 2 and end product, acetyl COA governed Citric Acid Cycle produces 12 ATP. Cumulatively in practice it comes 14 ATP for a one time full oxidation cycle and it only possible when we assume, 2.5 ATP per NADH molecule and 1.5 for each FADH2 molecule and 10 fro citric acid cycle, which seems to be irrational. But for better understanding we put this kind of assumption. However palmitate is 16 carbon containing saturated fatty acid.

So, for an even-numbered saturated fat (C2n) ("C" indicating the number of carbon atoms and noted 2n is in the subscript), n - 1 oxidations are required, and the final process yields an 1 more acetyl CoA i.e. for palmitate if 2n=16 then n=8, which required n-1 oxiation i.e 7, so there will be 7 FAD, 7 NADH and 8 acetyl COA which will produce 1.5 ATP, 2.5 ATP and 10 ATP respectively and cumulatively it will be calculated 108 where 2 ATP were used in the initial activation of fatty acid so 2 ATP will be subtracted and total number of ATP will become 106. But if you go with the thereotical yields and have larger production ATP source then values of NADH, FAD and ATP produced by the full rotation of citric acid cycle will produce 3, 2, 12 ATPs. Together ATP number will become 131 and 2 will be subtracted as required for initial activation of fatty acid so you will remain with 129

 

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Arun (askIITians forum expert)