All GRE Subject Test: Chemistry Resources
Example Question #2 : Carbohydrates
Which type of bond is created between carbohydrates and the sidechain amine of select asparagine residues in proteins?
Neither is correct
Both are correct
A glycosidic bond covalently joins a carbohydrate molecule to another molecule. An O-glycosidic bond is a covalent linkage between a carbohydrate and a protein, joining a serine or threonine hydroxyl side chain and a sugar (oxygen in the bond yields "O"). An N-glycosidic linkage involves bonding of a carbohydrate and a protein, joining an asparagine side chain amide and a sugar (nitrogen in the bond yields "N"). Thus, N-glycosidic is the correct answer.