Chapter 27, Problem 8P

Ethanol as a Source of Metabolic Energy (Integrates with Chapters 19 and 20.) Acetate produced in ethanol metabolism can be transformed into acetyl-COA by the acetyl thiokinase reaction:

$\text{Acetate }+\text{ATP }+\text{CoASH }\to \text{acetyle}-\text{CoA }+\text{ AMP }+{\text{ PP}}_{\text{i}}$Acetyle-CoA then can enter the citric acid cycle and undergo oxidation to 2 ${\text{CO}}_{\text{2}}$by this route, assuming oxidative phosphorylation is part of the process? (Assume all reactions prior to acetyl-CoA entering the citric acid cycle occur outside the mitochondrion). Per carbon atom, which is a better metabolic fuel, ethanol or glucose? That is, how many ATP equivalents per carbon atom are generated by combustion of glucose versus ethanol to ${\text{CO}}_{\text{2}}$?