Which Statement Is TRUE of Glycogen Synthesis and Breakdown

Multiple Choice

Which statement is TRUE of glycogen synthesis and breakdown?

A) Phosphorylation activates the enzyme responsible for breakdown, and inactivates the synthetic enzyme.
B) Synthesis is catalyzed by the same enzyme that catalyzes breakdown.
C) The glycogen molecule "grows" at its reducing end.
D) The immediate product of glycogen breakdown is free glucose.
E) Under normal circumstances, glycogen synthesis and glycogen breakdown occur simultaneously and at high rates.