Chemical Composition and Structure of Chitin Chitin is a long-chain polymer of N-acetylglucosamine, a derivative of glucose. It is a fibrous structural heteropolysaccharide composed of N-acetyl-D-glucosamine units and chemically classed as an aminopolysaccharide. The monomer units are joined together by glycosidic bonds to form a linear backbone. The molecular structure of chitin is very...