From palmitate (C16) in beta-oxidation, how many acetyl-CoA molecules are produced and how many beta-oxidation cycles occur?

• A. 7 acetyl-CoA and 7 beta-oxidation cycles
• B. 8 acetyl-CoA and 6 beta-oxidation cycles
• C. 9 acetyl-CoA and 7 beta-oxidation cycles
• D. 8 acetyl-CoA and 7 beta-oxidation cycles

Answer: (D)

In beta-oxidation, a saturated even-numbered fatty acid is chopped two carbons at a time, with each cycle yielding one acetyl-CoA. To find the total acetyl-CoA, divide the carbon count by two. The number of beta-oxidation cycles is the number of two-carbon removals, which for an even-chain fatty acid is one less than the number of acetyl-CoA units, because the final cleavage can release two acetyl-CoA from a 4-carbon piece in the last step.

For palmitate, with 16 carbons, you get 16/2 = 8 acetyl-CoA. The number of beta-oxidation cycles is 8 − 1 = 7. So the correct result is 8 acetyl-CoA and 7 beta-oxidation cycles.