Structural Biochemistry/Carbohydrates/Chitin

Introduction

Chitin is a nitrogen modified polysaccharide made up of N-acetylglucosamine, bound together in beta 1, 4 glucosidal bonds. Chitin is very similar in structure of cellulose; it has the additional amine component and hydroxyl substituent on each monomer. Chitin has an overall positive charge, making it great at binding to negatively charged objects, such as skin and proteins. It is insoluble in water and organic solvents. There are alpha, beta, and gamma forms of chitin. Alpha chitins are composed of alternating antiparallel polysaccharide strands mostly found in crustacean. Beta chitins are composed of parallel strands of polysaccharides, often found in squid. 2 parallel chains alternating with an antiparallel strand constitute gamma chitin and are found in fungi. One chitin derivative is chitosan, which is soluble in water and is made when chitin is placed in a chemical solution and well heated. Chitin has extensive medical uses, chitin when used during sutures increase healing by 50%, making the process shorter and less painful. Chitin can also be used for artificial blood vessels, antibacterial sponges, and dressings. Chitin can also act as a water purifier, it contains internal hooks which can remove impurities in water. In farming, chitin treated seeds tend to be resistant to fungus. In its unmodified form, chitin appears to be translucent, hard, and flexible. It mainly functions as the hard exterior of arthropods, and does a good job of protecting the soft interiors of these organisms from their harsh environment. It acts as structural support for organisms and prevents fluid loss in these organisms. http://academic.brooklyn.cuny.edu/biology/bio4fv/page/chitin.jpg [1] [2]