Kariuki M. answered • 06/12/21
Molecular Biologist with 10+ years of teaching biochemistry
How much ATP is made from oxidation is proportional to how many reduced carbons are present in the reduced metabolite. The more C-H bonds (most reduced version of Carbon) , more electrons will be generated and transferred to NADH and FADH2, which in turn, are able to generate more H+ in the ETC. So, more carbons, more electrons, more protons --> higher electrical and chemical gradient---> more energy to drive the highly endothermic ADP+ Pi = ATP reaction.
Palmitic acid = 16 carbons, and during every oxidation cycle, m the beta carbon (2nd carbon from the carbonyl carbon) of the current chain, gets oxidized by FAD, NAD+, and H20 (C-H bond to C=O bond), and the alpha and carbonyl carbons are released in the form of acetyl-CoA (2 carbons released every cycle). So, 1NADH,1FADH2, and one acetyl-coA for every cycle. How many cycles for 16 carbons?
For even-chain fatty acids, the number of cycles = (N-2/2) cycles where N = chain length.
For odd-chain, the formula changes to N-3/2
Number of cycles = (16-2/2) = 7 cycles, producing 7 NADH + 7FADH2, which enter the ETC
Number of acetyl-coA for even chain = N/2 = 16/2= 8 acetyl-coA, which enter the TCA cycle.
Final Math is as follows:
7 NADH X 2.5 ATP/NADH = 17.5 ATP
7 FADH2 X 1.5 ATP/NADH = 10.5 ATP
8 Acetyl-coA x 10ATPs/acetyl-coA = 80 ATP
TOTAL = 108 ATP
In theory, 108 ATPs can be made. How much is actually depends on the metabolic demand vs supply
