Chitin

Frae Wikipedia
Lowp tae: navigation, rake
Structur o the chitin molecule, shawin twa o the N-acetylglucosamine units that repeat tae form lang chains in β-1,4 linkage.

Chitin (C8H13O5N)n (/ˈktn/ KY-tin) is a lang-chain polymer o a N-acetylglucosamine, a derivative o glucose, and is foond in mony places throughoot the naitural warld.