Question

How many ATP would be produced from the oxidation of a 15 carbon monounsaturated fatty acid?

Please show your steps and explain!

Answer 1

A 15 carbon monounsaturated fatty acid produces 90.5 molecules of ATP. 15 carbon monounsaturated fatty acid is same way with 14 carbon monounsaturated fatty acid until three carbon propionyl CoA is produced which is ultimately converted into succinyl-CoA which enters into krebs cycle. Due to presence of one unsaturated beta carbon, one step is skipped. No FADH₂ is produced on that step. So, One less FADH₂ is produced in monounsaturated fatty acid.

Reaction	ATP yield	ATP consumed
Activation of fatty acid to fatty acyl CoA TCA cycle Oxidation of 6 acetyl CoA + 1 Succinyl COA	7 GTP= 7 6 FADH2 = 1.5×6 = 9 21 NADH2 = 2.5×21 = 52.5	-2
6 round of β-Oxidation cycle	Oxidation of 6 FADH2 1.5×6 = 9 Oxidation of 6 NADH 2.5×6 = 15
	Total ATP produced 92.5-2 = 90.5