Carbohydrate Metabolism Regulation Problem Set

Question 2: Enzyme Dephosphorylaton by Insulin Action

Of the enzymes of carbohydrate metabolism listed below, which are (de)phosphorylated in liver in response to insulin signaling?

  1. Glycogen synthase

  2. Glycogen phosphorylase

  3. Phosphofructokinase-1 (PFK-1)

  4. Phosphofructokinase-2 (PFK-2)

  5. Pyruvate kinase

    Four of these enzymes are directly modified via dephosphorylation (1, 2, 4, and 5). Three of the dephosphorylation events activate the affected enzyme, but one (glycogen phosphorylase) is inhibited by this modification. Again, this makes sense in view of insulin's role to store, not mobilize glucose. The remaining enzyme is affected indirectly by insulin, but how?

Problem 2 | Tutorial | Problem 3


The Biology Project Home > Biochemistry > Regulation of Carbohydrate Metabolism > Problem Set

The Biology Project
The University of Arizona
March 16, 2001
Revised: August, 2004
Contact the Development Team
All contents copyright © 2000-2004. All rights reserved.