Fatty acids usually have an even number of carbons in their structures. Catabolism of fatty acids produces two-carbon fragments that are converted to acetyl CoA molecules. What is the most likely way in which these acetyl CoA molecules would be metabolised in aerobic cellular respiration?
A) They would directly enter the electron transport chain.
B) They would directly enter the energy-yielding phase of glycolysis.
C) They would be converted to pyruvate and then undergo pyruvate oxidation upon transport into mitochondria.
D) They would directly enter the citric acid cycle.

Question

Quizplus · Accepted Answer

Acetyl CoA is the molecule that enters the citric acid cycle. This is the most likely way in which these acetyl CoA molecules would be metabolized in aerobic cellular respiration. The citric acid cycle produces electron carriers that then enter the electron transport chain, which generates ATP. Therefore, option A is incorrect. Acetyl CoA cannot directly enter the energy-yielding phase of glycolysis, making option B wrong. While it is possible for pyruvate to be converted to acetyl CoA, it is not the usual way it occurs. Hence, option C is also incorrect.

Fatty Acids Usually Have an Even Number of Carbons in Their