Reaction catalyzed by flavonol 3-O-glucosyltransferase (2.4.1.91)

		+			=			+		quercetin 3,7-O-di-beta-D-glucoside
	UDP-alpha-D-glucose	+		quercetin 7-O-beta-D-glucoside	=		UDP	+		quercetin 3,7-O-di-beta-D-glucoside