Adrenaline stimulates glycogen breakdown in skeletal muscle cells by ultimately activating glycogen phosphorylase, the enzyme that breaks down glycogen, as depicted in the figure below. adrenaline activated a subunit of stimulatory G protein (G) CYTOSOL GTP activated GPCR (adrenergic receptor) activated adenylyl cyclase ATP Inactive PKA *** cyclic AMP CAMP active PKA ATP active phosphorylase kinase active glycogen phosphorylase Inactive phosphorylase kinase inactive glycogen phosphorylase GLYCOGEN BREAKDOWN phosphorylase Linase phosphorylase ATP Inactive glycogen phosphorylase GLYCOGEN BREAKDOWN Which of the following statements is false? A constitutively active mutant form of PKA in skeletal muscle cells would not increase the affinity of adrenaline for the adrenergic receptor. A constitutively active mutant form of PKA in skeletal muscle cells would lead to an excess in the amount of glycogen available A constitutively active mutant form of PKA in skeletal muscle cells would lead to a decrease in the amount of unphosphorylated phosphorylase kinase. A constitutively active mutant form of PKA in skeletal muscle cells would increase the amount of phosphorylated glycogen phosphorylase. A constitutively active mutant form of PKA in skeletal muscle cells would lead to an excess in the amount of glucose available.