Schematic representation of the nucleotide sugar biosynthesis as metabolic link between glucose and glycosylation, an essential cellular process involved in pluripotency, differentiation, and other stem cell functions. Abbreviations: ATP, adenosine 5′-triphosphate; CDP-Rbo, CDP-ribitol; CMP-Neu5Ac, CMP-N-acetylneuraminic acid; CoA, coenzyme A; GDP-Fuc, GDP-fucose; GDP-Man, GDP-mannose; PPP, pentose phosphate pathway; TCA cycle, tricarboxylic acid cycle; UDP-Gal, UDP-galactose; UDP-Glc, UDP-glucose; UDP-GlcA, UDP-glucuronic acid; UDP-GalNAc, UDP-N-acetylgalactosamine; UDP-GlcNAc, UDP-N-acetylglucosamine; UDP-Xyl, UDP-xylose.