Insulin's effects on liver metabolism
Which change occurs in hepatocytes when insulin levels rise after a meal?
Answer B: explanation for every choice
A
Glycogen phosphorylase is activated by glucagon-driven phosphorylation. Insulin promotes its dephosphorylation, which inactivates it.
B
Correct. Insulin promotes dephosphorylation of the bifunctional enzyme, activating its PFK-2 activity. Fructose-2,6-bisphosphate then rises and activates PFK-1, speeding glycolysis.
C
Gluconeogenesis is suppressed after a meal. Fructose-2,6-bisphosphate also inhibits fructose-1,6-bisphosphatase.
D
Ketogenesis increases when insulin is low, as in fasting or uncontrolled type 1 diabetes.
TakeawayInsulin → dephosphorylation → glycolysis and storage on. Glucagon → phosphorylation → glucose release on.
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Reviewed 2026-11-05 by a medical student. Spot an error? Report it with question ID bb11.