Question

Show your work and share your logic with respect to what reactions use either ATP of reduced electron carriers and what reactions produce either ATP or reduced electron carriers. Then show the final NET total of ATP’s produced for that molecule as well as the average number of ATP/Carbon of the original molecule. Note that I am asking you to think through total oxidation of the fatty acid to CO2.

Calculate the net ATPs obtained with a 18:1∆9 fatty acid with a single branch at carbon 3.

Answer 1

Fatty acid with C18:1 ∆9 which indicates it's oleic acid

So complete oxidation of oleic acid release how much ATP?

Oleic acid undergo beta oxidation Process to release acetyl coA

So total 8 round of beta oxidation cycle will to form 9 molecule of acetyl co A with release of total 8 NADH and 8 FADH2 ( as one cycle of beta oxidation release 1 NADH and 1 FADH2)

Now 9 molecule of acetyl coA enter into TCA cycle and run 9 round TCA cycle, so total 27 NADH and 9 FADH2 and 9 ATP molecule formed.

Till now, total 36 NADH and 17 FADH2 and 9 ATP are formed.

Further NADH and FADH2 enter into Electron transport chain to form ATP

One NADH form 2.5 ATP so total 36x 2.5= 90 ATP and one FADH2 form 1.5 ATP so total 17x 1.5 = 25.5 ATP

So final ATP= 90+ 25.5+ 9 = 124.5

(Kindly note, here we consider that 1 NADH form 2.5 ATP and 1 FADH2 form 1.5 ATP according to Lehninger book)

Hope it's clear ...thanks