CHITIN

1. It is polymer of N-acetyl-D-glucosamine.
2. It is a structural homopolysaccharide found in the fungal walls as fungus cellulose and as chitin in the exoskeleton of arthropods (crustaceans, insects).
3. Chitin is insoluble in water and It is a polymer of N-acetylglucosamine.
4. Chitin is the second most abundant organic material.
5. Where hardness is required, chitin is impregnated with calcium carbonate and fibrous proteins.
6. It is impermeable to water and prevents loss of water through evaporation.