Reaction catalyzed by medium-chain acyl-CoA dehydrogenase (1.3.8.7)

		+			=		+ trans-dodec-2-enoyl-CoA reduced electron-transfer flavoprotein
	dodecanoyl-CoA	+		electron-transfer flavoprotein	=		+ trans-dodec-2-enoyl-CoA reduced electron-transfer flavoprotein