What Carbohydrates Make up the Exoskeleton of an Insect?

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The major structural component of an insect's outer covering is derived from a substance found abundantly in nature called chitin. It is a polysaccaride (a type of carbohydrate), that is also found in other animals such as crustaceans and arachnids and is extremely useful to the cosmetic and medical industry.


Carbohydrates are the main source of energy for all living things, whether plant or animal. A carbohydrate is comprised of carbon, hydrogen and oxygen (or simply, carbon and water). The simplest unit of a carbohydrate is called a monosaccaride, an example of which is glucose. A disaccaride is two monosaccarides joined by a covalent (double) bond, as in sucrose, for example. (Covalent bonds are energy storage molecules. When these break, energy is released). Several monosaccarides joined together form polysaccarides. Chitin is an example of a polysaccaride.

Functions of Carbohydrates

Monosaccarides join together to form different kinds of polysaccarides including starch, cellulose glycogen and chitin. Starch is a storage product of plants. Cellulose is a supporting material for plants. Glycogen is a storage product of animals. Chitin is the main structural component of exoskeletons.


A tarantula's exoskeleton is composed of chitin.
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This polysaccaride contains nitrogen and is the principal component of exoskeletons for many arthropods and cell walls of certain fungi. An arthropod is a phylum of animals with a chitinous shell that molts and includes insects, arachnids (spiders), crustaceans (crabs, lobsters), and myriapods (many legged insects such as centipedes). Chemically, chitin is known as poly (N-acetlyglucosamine).

Uses for Chitin

Chitin is abundantly found in nature (second to cellulose). It is usually present with other polysaccarides and proteins. It can be isolated and is often a key component in waste water clearing, cosmetics, medical and veterinary applications (particularly in accelerating wound healing).


About the Author

Maureen Graham has been a freelance writer since 2008. She has been published in "Family Planning Perspectives" and "Journal of Biosocial Science." Graham holds a Master of Science in epidemiology from the Harvard School of Public Health.

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