Repeated USMLE Questions Step 1- 173

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

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