2.3.1.157 glucosamine-1-phosphate N-acetyltransferase UDP-GlcNAc biosynthesis UDP-GlcNAc biosynthesis 2.6.1.16 glutamine-fructose-6-phosphate transaminase (isomerizing) UDP-GlcNAc biosynthesis UDP-GlcNAc biosynthesis 2.7.7.23 UDP-N-acetylglucosamine diphosphorylase UDP-GlcNAc biosynthesis UDP-GlcNAc biosynthesis 5.4.2.10 phosphoglucosamine mutase UDP-GlcNAc biosynthesis UDP-GlcNAc biosynthesis