Chitin | Definition, Structure, Function & Examples

By | July 26, 2019

Chitin Definition:

Chitin is a protective, tough and semitransparent polysaccharide containing the principal of Arthropod exoskeletons and the cell walls of specific Fungi. Every form of living organisms such as spiders, butterflies, and Beetles, Lobsters, shrimp, and crabs contain some of the chitin in their secure Armors.

Technically, it is a Polysaccharide, which is made up of N-Acetylglucosamine, such as the structure of cellulose in plants.  In humans, it is responsible for some forms of Asthma.

It is the main part of the exoskeleton of insects to protect their delicate soft tissues. The hard-outer shell of arthropods and insects is primarily made by chitin, which is a natural biopolymer occurs. It is also found in the certain hard structure of invertebrates and fish. c is second to only cellulose in abundance. In the term of the biosphere, organisms synthesize over one billion of chitin each year.

Structure of Chitin:

Chitin Structure: Naturally, it is the most unlimited amino polysaccharide and produces almost as much as cellulose. It is mostly contained by exoskeletons of arthropods, cell walls of fungi and nematode eggshells. It is composed of large of alternate N-Acetylglucosamine residues, which has a link of B-(1-4) glycoside bonds. However, by chitinase treatment, hydrolysis leads to the release of glucosamine to N-Acetylglucosamine.


In the result, Glucosamine may be a significant portion of the polymer. Since tobacco solids, NMR analysis Hornworm cuticle preparations suggest that it is little or no Glucosamine formed. Polymers chitins have to make microfibrils of ~3 nm in diameter which is stable by hydrogen bonds exist between carbonyl and the amine.

By the suggestion of X-ray diffraction analysis, chitins are a polymorphic substance which occurs in three different crystallines, as a-, b- and y- chitin. They are different in the form of hydration degree, in the size of a specific cell, and in the number of chain of chitin per unit cell.


Function of Chitin

Chitin Function is described below:

On outside the body, the skeleton appears hard because of it is present that is known as its tough elastic properties. However, it is a dominant substance.

Although, other compounds such as calcium carbonate and proteins also perform a necessary role in the formation of an exoskeleton. An exoskeleton, the main function of chitin is to keep the soft tissues save from any type of damage.

It is also acted as a watertight barrier against dehydration. It protects these specific tissues from dryness.

It also plays an important role in defense mechanism from predation, because predators exert a force of compression on the exoskeleton.


Examples of Chitin

Chitin in Arthropods

One of the foremost diverse teams of animals within the world is that the Arthropods. Arthropods are invertebrate animals that have a segmental body set up and a tough frame made from chitins and numerous proteins. Arthropods exist everyplace, from rock bottom of the ocean to highest places organisms inhabit. Arthropods additionally vary in size from microscopic mites that live at the bottom of hairs to large crabs and insects that may be meters long.

The exoskeletons of all of those creatures carry with it chitin deposited in conjunction with structural

. Mixed with completely different proteins, additionally, it makes the wings of the many insects as a more versatile material. The ability of chitin to be wrought into these completely different forms has allowed the arthropods to evolve into millions of different forms.


Chitin in Fungi

In fungi, chitins are employed to make a semipermeable membrane. very similar to cellulose in plants, the chitin is deposited extracellularly with proteins and different molecules. This forms a rigid cell wall between cells, that facilitate the organisms retain their form.

Very similar to in plant cells, water will be preserved within the cells to make water pressure against the cell wall. this can be called turgor pressure and adds to the strength of every cell. Fungi are capable to erupt multiple layers of leaf litter as they grow, which may weigh many pounds. The chitinous structure is very diverse.


Chitin in Mollusks

Chitins is seen in an exceeding variety of different forms within the mollusks. Chitins is employed in together in lower mollusks and also in the derived cephalopods. In mollusks like snails, chitin could be a part of the radulae, an organ that appears sort of a spiked tongue.

The mollusks use the radulae to scrape alga and different food from the arduous surfaces it grows on. The cephalopods additionally use chitins, however, to create a beak which might be used to bite through the arduous shells of their prey items. Ironically, most of the prey things are arthropods, and their shells are made up of chitins.


Chitin Food:

It is a natural biopolymer which is the second most abundant. Application of chitins food is processing aids receives considerable attention as exotic synthesis are losing their appeal in recent years. It is mostly used as stabilizer and thickeners of food. It also contains many applications such as a healthy supplementary.

It is often used to manage body weight and cholesterol levels. Some other  uses are:

  • Support for kidney functions
  • Healthy cholesterol level management
  • Skin health support
  • Weight management


Chitin vs Cellulose

Two main structural polymers found in nature are cellulose and chitin. Cellulose is a polysaccharide which is made up of a linear chain of D-glucose monomers. It is also a substance that contains modified glucose monomers, which are derived from glucose called N-Acetylglucosamine. Cellulose is the first most abundant natural polymer. While It is second most abundant only to cellulose. The difference between chitin and cellulose is that it is the main organic polymer which found in the cell wall of fungi and cellulose is the significant organic polymer which found in primary cell walls of the plant cells.