calculating NET total amt of ATP from fatty acids

step 1

count number of b-oxidation cycles to oxidize fatty acid

• palmitic acid (C16): seven cycles

each oxi-cycle:

• an acyl CoA is shared by 2 C’s

• produces 1 FADH2, 1 NADH, 1 acetyl CoA

  • each acetyl CoA prod: 3 NADH, 1 FADH2, 1 GTP

NADH: 2.5 ATP/NADH

FADH2: 1.5 ATP/FADH2

GTP: 1 ATP/GTP

number of b-oxi cycles

divide number of carbons by 2, subtract 1

• e.g. C16 → 16/2 = 8, 8-1 =7 cycles to get 8 acetyl CoA

for each b-oxi cycle: how much ATP?

4 ATP per cycle (one FADH2, one NADH)

how many ATP from one acetyl CoA?

10 ATP (3 NADH, 1 FADH2, 1 GTP)

presence of C=C (double bonds)

each double bond subtracts 1.5 ATP from total

activation of (unsaturated) acid to (unsaturated) CoA consumes "2" ATP:

• When ATP is catalyzed to AMP (releasing one PPi ), 2 molecules of orthophosphate (Pi) is produced, which is equivalent to using 2 ATP molecules

• ATP production is reduced by 2 ATP