Concept #1: Glycogen Phosphorylase

Concept #2: Two Isozymes of Glycogen Phosphorylase

Concept #3: Phosphorylase a & Phosphorylase b

Practice: Glycogen phosphorylase is an enzyme involved in glycogen metabolism that’s regulated by phosphorylation. Phosphorylation on serine residues results in more enzyme activity, while the dephosphorylated enzyme has little to no activity. What result would you expect on activity if the serine residues that served as phosphorylation sites on glycogen phosphorylase were mutated to aspartate residues?