Gluconeogenesis vs. glycogenolysis: which enzymes?
Which enzyme is required for hepatic gluconeogenesis but not for hepatic glycogenolysis?
Answer C: explanation for every choice
A
Glucose-6-phosphatase is the final step of both pathways, releasing free glucose from the liver.
B
Glycogen phosphorylase is required only for glycogenolysis.
C
Correct. Pyruvate carboxylase converts pyruvate to oxaloacetate in mitochondria, the first bypass step of gluconeogenesis. It is activated by acetyl-CoA.
D
Phosphoglucomutase converts glucose-1-phosphate to glucose-6-phosphate during glycogenolysis.
TakeawayBoth pathways end at glucose-6-phosphatase. Only gluconeogenesis needs pyruvate carboxylase, PEPCK, and fructose-1,6-bisphosphatase.
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Reviewed 2026-11-05 by a medical student. Spot an error? Report it with question ID bb10.