Chitin is a linear homopolymer of N-acetyl-β-D-glucosamine residues linked by β-1,4 glycosidic bonds to form microfibrils. These become the structural component to cell walls and many extracellular matrices such as cuticles and exoskeleton of insects. This process is highly conserved and occurs in many different organisms including insects and fungi. Chitin exist in several crystaline forms termed α, β and γ chitin, the most abundant being α chitin (reviewed in [Merzendorfer11]). Chitin and lipids are secreted by epidermal cells and form the basis for the cuticle material and layered structure.

Chitin Biosynthesis References