Question

What is chitin?

Answer 1

The major constituent in the exoskeleton of arthropods and the cell walls of fungi, ‘Chitin’ is a fibrous substance consisting of polysaccharides. It is the main component of the exoskeletons of arthropods, such as the shells of crustaceans and the outer coverings of insects. Chitin is a tough, semi-transparent substance.

Complete step by step answer:
Chitin is a nitrogenous polysaccharide and also a natural polymer. Some of the characteristics of chitin are discussed below:
A derivative of glucose, N-acetyl glucosamine is the monomer unit of chitin. The exoskeletons of arthropods, such as crustaceans and insects, the radula of mollusks, cephalopod beaks, cell walls in fungi, and the scales of fish are primarily made up of chitin.
The units of N-acetyl-D-glucosamine (2-(acetyl amino-2-deoxy-D-glucose) synthesized to form chitin, a modified polysaccharide that contains nitrogen; it has β-(1→4)-linkages with covalent bonding which is present in it.
Chitin is an important source of carbon and nitrogen for marine organisms and is one of the most abundant renewable polymers. The chitinolytic bacteria play a significant role in the process of chitin degradation which is a key step in the cycling of nutrients in the oceans.

Note:
Chitin is one of the most important biopolymers in nature.
It supports the cuticles of the epidermis and trachea as well as the peritrophic matrices lining the gut epithelium.
Chitin is harder and more stable than cellulose as the hydroxyl group in the chitin monomer is replaced with an acetyl amine group, resulting in a stronger hydrogen bond between the bordering polymers.
The enzyme chitinase attacks the β1→4 glycosidic bond in chitin and hence the polymer breaks.