Reaction catalyzed by 24-methylenesterol C-methyltransferase (2.1.1.143)

		+			=			+
	S-adenosyl-L-methionine	+		24-methylene-cholesta-5,7-dien-3beta-ol	=		S-adenosyl-L-homocysteine	+		cholesta-8,24-dien-3beta-ol