Question

11. If Lignoceryl-CoA had two double bonds at carbon 6 and carbon 18 (24:246,18), then how many total ATP molecules would be produced by its complete beta-oxidation (including beta-oxidation itself and other subsequent metabolic processes)? Do not take into account the ATP required for fatty acid activation. A) 161 ATP D) 160 ATP ON B) 151 ATP E) None of the above C) 41 ATP

PLEASE ANSWER NUMBER 11

Answer 1

Beta oxidation is a mitochondrial process that converts fatty acid molecules into acetyl groups attach to co-enzyme A.

Acetyl Co-A enters the Kreb's cycle, where it is oxidized to Co2 and water and the enrgy relaeased is captured in the form of ATP molecules, In addition to reduction of electron carriers such as FAD+ or NAD+ to FADH2 or NADH respectively.

The FADH2 or NADH are then used during oxidative phosphorylation to generate energy rich ATPs.

In order to answer this question,

As Lignoceryl Co-A is unstaturated even number carbon containign fatty acid so, ignoring the fact that 2 ATPs would be consumed in fatty acid activation as stated.

Step1: For each round of Beta oxideation of 2carbon atoms are cleaved form a fatty acid

for even numberchains

No of rounds will be= n/2 -1

= 24/2-1

= 11(12 acetyl co-A formed and took 11 rounds after cleaving)

Now to undergo oxidative phosphorylation

1 FADH2 yeilds= 1.5 ATP or 2ATP

1NADH yeilds = 2.5 ATP or 3 ATP

Acetol-CoA yeilds= 10ATP or 12 ATP

Since LInoceryl Co-A undego 11 rounds so,

Case1:

If it yeilds 1.5 FADH2, 2.5 ATP for NADH and 10 ATP for Acetyl co-A then:

(1.5*11 + 2.5*11 + 10*11)= 154 ATP molecules

Now as it foms two double bonds so we subtract for 2 unsaturate bonds (for 1 unsaturated bond 2 ATp's are consumed) so , ATP moleules produced is 150 ATP molecules.

Case2:

If it yeilds 2 FADH2, 3 ATP for NADH and 12 for Acetyl Co-A then:

(2*11+3*11+12*11) = 187 ATP molecules.

Now as it forms two double bonds so we subtract for 2 unsaturated bonds (for 1 unsaturated vond 2 ATP's are consumed) so, ATP produced is 183 ATP molecules

So the answer is (E) None of the above