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Fungi cell wall is also composed of chitin that binds to the glucan to impart rigidity. Chitin is a polymer which is composed of β (1–4) linked N-acetylglucosamine. It is synthesized from the substrate known as UDP-N-acetylglucosamine by an enzyme called chitin synthase. Beside the fungal cell wall, chitin is also found in crustaceans and insects.

Chitosan is also found in the inner layer of fungal cell wall. But mostly chitin is deacylated to form chitosan. Structurally, chitosan is composed of β (1-4) N-acetylglucosamine and more than 50% glucosamine. Both chitin and chitosan provide structure and support to cell wall. The ratio of chitin/chitosan varies between different parts of the fungi such as, spore, hyphae and among the different species. For example, 12% chitin is found in spore while 40% in hyphae [42, 45–47].