Chitin (Gr. Heaton — tunic)

Chitin (Gr. Chiton - Tunica)

Chitin is an insoluble protein-polysaccharide complex that forms the exoskeleton of arthropods and the cell walls of some fungi.

Chitin is the second most abundant natural polymer after cellulose. It forms the basis of the exoskeleton of crustaceans, insects and other arthropods. Chitin is also part of the cell walls of fungi, in particular fungi of the Zygomycetes division.

The chitin molecule is a linear polysaccharide consisting of N-acetylglucosamine residues. These residues are connected by β-1,4-glycosidic bonds.

Chitin provides protection and support for arthropods. It gives the exoskeleton hardness and strength. At the same time, the chitinous exoskeleton is elastic and allows the animal to move. In crustaceans, chitin is periodically shed during molting.

Thus, chitin is an important structural polymer that plays a key role in the defense of arthropods and fungi. Its unique physicochemical properties make chitin an indispensable component of the exoskeleton of invertebrate animals.