Question

If a drug that was an inhibitor of PP1 activity was ingested by a person

Glycogen phosphorylase would be de-phosphorylated and inactive.
Glycogen phosphorylase would be de-phosphorylated and retain some activity.
Glycogen phosphorylase would remain phosphorylated and inactive.
Glycogen phosphorylase would remain phosphorylated and retain some activity.

Answer 1

The correct answer is: Glycogen phosphorylase would remain phosphorylated and retain some activity.

Glycogen phosphorylase is directly involved in the regulation of glucose levels since it is a glucose sensor in liver cells: when glucose levels are low, phosphorylase is active and it has PP1 bound to it (phosphatase activity of PP1 is prevented). Therefore, there phosphorylase a will accelerate glycogen breakdown.