Chitin is a complex molecule, AKA a polymer. Chitin can be found in crustaceans, such as crabs, lobsters, and shrimp. It can also be found in insects, worms, and fungus, or mushrooms. The thing about chitin is that it is a natural polymer, which means that it is found in nature.

In the creatures where chitin is found, it is in different percentages depending on the place. As you can see from the chart of all the creatures, crabs contain the largest percentage of chitin.
(Muzzarelli: All numbers are approximate)

Fungi 5-20%
Worms 20-38%
Squids/Octopus 3-20%
Scorpions 30%
Spiders 38%
Cockroaches 35%
Water Beetle 37%
Silk Worm 44%
Hermit Crab 69%
Edible Crab 70%

The structure of chitin is very similar to cellulose

As you can see below:



What makes them so similar is that both are b(beta)1-4 linked. To the left is a small section of the chitin molecule with the carbon atoms labeled with numbers to show the order. The oxygen is not labeled but is holding the number two spot.

The difference between the cellulose molecule and the chitin molecule is that chitin has an amide group instead of a hydroxyl group (alcohol), which cellulose has.

To get a three dimensional image of cellulose, and all the information you could possibly want on this natural polymer
click here


Chitosan is a polymer derived from chitin and is used in applications from health care to agriculture to dyes for fabrics. There are even medical applications and companies who use products made with chitosan as part of weight loss programs.

Chitosan is very similar to chitin, see below. The difference is that chitosan has an amine group instead of an amide group. This just means that chitosan doesn't have any carbons double bonded to oxygen and chitin does.


Uses of chitin and its derivatives

One of the more important things that chitin, and its products, could be used for is in treating burn patients. Chitin has a remarkable compatibility with living tissue, and has been looked at for its ability to increase the healing of wounds. There is also evidence that chitosan can reduce serum cholesterol levels. More research has also indicated that chitosan can increase crop yields, and clean and clear up pools.

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