So protein kinase A in the active form goes on and phosphorylates an enzyme called phosphorylase kinase and that transforms it into the active form. Now, phosphoralase kinase in the active form goes on to activate phosphorate, phosphorase B and that transforms it into the much more active phosphorase A. Remember, phosphorase A exists predominantly in the relaxed state and so it's fully active. And it's phosphorase A that is responsible for actually initiating the process of glycogen breakdown. So this allows, let's say, the liver cell to actually break down the glycogen into glucose molecules and then release the glucose into the blood plasma to help regulate the concentration of glucose in our blood during times of fasting or exercise. At the same exact time, the PKA also actually phosphorylates glycogen synthase A and that transforms it into the act from the active form into the inactive form, glycogen synthase B.