the phosphorylated form of liver glycogen phosphorylase ( alpha-1,4-glucan : orthophosphate alpha-glucosyl-transferase , ec 2.4.1.1 ) ( phosphorylase a ) is active and easily measured while the dephosphorylated form ( phosphorylase b ) , in contrast to the muscle enzyme , has been reported to be essentially inactive even in the presence of amp .
C0017916
phosphorylase
C0031711
phosphorylase b