Reaction catalyzed by glycogen phosphorylase (2.4.1.1)

		+			=		alpha-D-xylose-(1,4-alpha-D-glucosyl)n	+
	(1,4-alpha-D-glucosyl)n-1	+		alpha-D-xylose 1-phosphate	=		alpha-D-xylose-(1,4-alpha-D-glucosyl)n	+		phosphate