Many other common diseases are caused by autoimmunity such as juvenile diabetes and low thyroid disease. It has been recently discovered that some persons who suffer with hives or angioedema also have an autoimmune disease. In these cases, autoantibodies have been formed that bind to the Fc-receptor on mast cells.
Lesson Summary. Chitin is a primary component in the exoskeletons of arthropods and crustaceans and is also found in the cell walls of fungi. It's a polysaccharide, and it's excreted by the epidermal cells in arthropods. But, it can't grow with the animal, so shedding becomes necessary.
Chitin is to the animal kingdom that cellulose is to the plant kingdom. Chitin is found in shells of crustaceans and in the exoskeleton of insects. Chitin is a polymer of N-acetyl-D-glucosamine with NI, NII-diacetylchitobiose being the repeating unit.Like cellulose, intramolecular hydrogen bonding is important for the structure of chitin.hitin is found in shells of crustaceans and in the exoskeleton of insects. Chitin is a polymer of N-acetyl-D-glucosamine with NI, NII-diacetylchitobiose being the repeating unit. Like cellulose, intramolecular hydrogen bonding is important for the structure of chitin.