these observations demonstrate that : ( a ) sugar moieties of microsomal glycoproteins are exposed only on the luminal surface of the membranes and ( b ) microsomal membrane glycoproteins have incomplete carbohydrate chains without the characteristic terminal trisaccharides n-acetylglucosamine comes from galactose comes from sialic acid or fucose present in most glycoproteins secreted by the liver .
C0025248
membrane glycoproteins
C0017968
glycoproteins