ATP yield in Beta oxidation of palmitic acid ?: (A) 106 ATP, (B) 102 ATP, (C) 120 ATP, (D) 110 ATP
Answer is A. Energetics of Beta Oxidation (ATP Yield) - Palmitic acid (16 C) needs 7 cycles of beta oxidation. So, it gives rise to 8 molecules of acetyl CoA. Every molecule of acetyl CoA when oxidised in the TCA cycle gives 10 molecules of ATP. Each molecule of FADH2 produces 1.5 molecules of ATP and each NADH generates 2.5 molecules of ATP, when oxidised in the electron transpo chain. Hence, the energy yield from one molecule of palmitate may be calculated as: 8 acetyl CoA x 10 = 80 ATP 7 FADH2 x 1.5 = 10.5 ATP 7 NADH x 2.5 = 17.5 ATP Gross total = 108 ATP Net yield = 108-2 = 106 ATP. Ref: DM VASUDEVAN TEXTBOOK OF BIOCHEMISTRY, EIGHTH EDITION,PG.NO.,196.