Chitinn is a long-chain
polymer of a
N-acetylglucosamine, a derivative of
glucose, and is found in many places throughout the natural world. It is the main component of the
cell walls of
fungi, the
exoskeletons of
arthropods such as
crustaceans and
insects, the
radulas of
mollusks, and the beaks of
cephalopods, including
squid and
octopuses. In terms of structure, chitin may be compared to the polysaccharide
cellulose and, in terms of function, to the protein
keratin. Chitin has also proven useful for several medical and industrial purposes.