Repeated USMLE Questions Step 1- 207

Gluconeogenesis is a metabolic process in which glucose is generated from non-carbohydrate carbon substrates.

Which one of the following substrates does NOT share its carbon in glucose skeleton but rather contributes as an energy source for gluconeogenesis?

A- Acetyl CoA

B- Alpha-ketoglutarate

C- Fumarate

D- Oxaloacetate

E- Succinyl CoA






Acetyl CoA is an energy source as it generates 12 ATP for each citric acid cycle. Other substrates contribute their carbon in glucose skeleton.

The correct answer is A