<Li> In S - glycosylation, a beta - GlcNAc is attached to the sulfur atom of a cysteine residue . </Li> <Li> In glypiation, a GPI glycolipid is attached to the C - terminus of a polypeptide, serving as a membrane anchor . </Li> <Li> In glycation, also known as non-enzymatic glycosylation, sugars are covalently bonded to a protein or lipid molecule, without the controlling action of an enzyme, but through a Maillard reaction . </Li> <P> Monosaccharides commonly found in eukaryotic glycoproteins include: </P>

Where are sugars added to proteins to form glycoprotein