Answer to Question #101635 in Chemistry for NIBEDITA RUDRA

Question

Compare the energetics of metabolic oxidation of glucose and a fatty acid.

Answer 1

Metabolic oxidation of glucose occurs during glycolysis and TCA cycle. At first, glucose breakdown is associated with the formation of pyruvate that is further transformed into acetyl-CoA. Oxidation of one glucose molecule is associated with the formation of 32 ATP molecules.

Fatty acids oxidation is performed by in beta-oxidation reactions resulting in the formation of acetyl-CoA entering TCA. As a result, both glucose and fatty-acids undergo metabolic oxidation in TCA. However, oxidation of one molecule of palmitate results in the formation of 106 ATP molecules.

Therefore, although metabolic oxidation of glucose and fatty acid is associated with the formation of acetyl-CoA that enters the TCA cycle, the oxidation of one fatty acid results in the production of a greater number of ATP molecules.