Total acetyl-CoA yield from palmitate Palmitic acid (C16:0) undergoes seven rounds of mitochondrial β-oxidation. How many molecules of acetyl-CoA are ultimately produced from the complete oxidation of one palmitoyl-CoA?

Introduction / Context:Computing products from β-oxidation is essential for ATP yield calculations. Even-chain saturated fatty acids like palmitate are fully converted to acetyl-CoA units.

Given Data / Assumptions:

• Palmitate has 16 carbons.
• Each β-oxidation cycle removes two carbons as acetyl-CoA.
• Number of cycles for an even-chain fatty acid = (n/2) − 1.

Concept / Approach:Total acetyl-CoA units from an even-chain fatty acid = n/2. For palmitate, n = 16, giving 8 acetyl-CoA. The final thiolysis produces two acetyl-CoA from a C4 intermediate after seven cycles.

Step-by-Step Solution:Cycles = (16/2) − 1 = 7 cycles.Per cycle: 1 acetyl-CoA liberated; final cleavage yields 2 acetyl-CoA from the last C4 fragment.Total acetyl-CoA = 8.

Verification / Alternative check:ATP yield calculation for palmitate relies on 8 acetyl-CoA entering the TCA cycle plus 7 FADH2 and 7 NADH from β-oxidation cycles.

Why Other Options Are Wrong:6 or 7 underestimate the correct n/2 value.9 or 16 have no basis in β-oxidation stoichiometry.

Common Pitfalls:Confusing number of cycles with number of acetyl-CoA; forgetting the last step yields two acetyl-CoA from C4.

Final Answer:8.