Identify the true statements regarding liver glycogen phosphorylase a. Protein phosphatase 1 is abbreviated PP1. The binding of glucose to liver phosphorylase a shifts the equilibrium from the active form to the inactive form. Liver phosphorylase a concentration decreases when glucose enters the blood. As the concentration of phosphorylase a decreases, the activity of glycogen synthase increases. Liver phosphorylase a is regulated by AMP, adenosine monophosphate. When PP1 is bound to phosphorylase a, both PP1 and phosphorylase a are active.