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Chitin (C 8 H 13 O 5 N) n (/ ˈ k aɪ t ɪ n / KY-tin) is a long-chain polymer of N-acetylglucosamine, an amide derivative of glucose. Chitin is the second most abundant polysaccharide in nature (behind only cellulose); an estimated 1 billion tons of chitin are produced each year in the biosphere. [1]
Arthropod cuticle is a biological composite material, consisting of two main portions: fibrous chains of alpha-chitin within a matrix of silk-like and globular proteins, of which the best-known is the rubbery protein called resilin. The relative abundance of these two main components varies from approximately 50/50 to 80/20 chitin protein, with ...
Like cellulose, chitin is an abundant biopolymer that is relatively resistant to degradation. [17] Many mammals can digest chitin and the specific chitinase levels in vertebrate species are adapted to their feeding behaviours. [18] Certain fish are able to digest chitin. [19] Chitinases have been isolated from the stomachs of mammals, including ...
Each of the two auricles collects blood from the gills on one side, while the muscular ventricle pumps blood through the aorta and round the body. The excretory system consists of two nephridia , which connect to the pericardial cavity around the heart, and remove excreta through a pore that opens near the rear of the mantle cavity.
A number of studies have measured the bioavailability of glucosamine after oral administration to horses. When given as a single oral dose (9 g) with or without chondroitin sulfate (3 g) to ten horses, glucosamine (hydrochloride) was detected in the blood with a maximum level of 10.6 ± 6.9 μg/mL at two hours after dosing. [47]
However, a growing body of molecular and biological data indicate that at least certain shell features have evolved many times, independently. [38] The nacreous layer of shells is a complex structure, but rather than being difficult to evolve, it has in fact arisen many times convergently. [ 38 ]
Chitin Synthase is manufactured in the rough endoplasmic reticulum of fungi as the inactive form, zymogen. The zymogen is then packaged into chitosomes in the golgi apparatus. Chitosomes bring the zymogen to the hyphal tip of a mold or yeast cell membrane. Chitin synthase is placed into the interior side of the cell membrane and then activated.
It contains a large number of plasma cells and is the main secretory body of antibodies. [7] Alongside these primary and secondary lymphoid organs, there is also the lymphatic circulatory system of vessels and capillaries that communicate with the blood supply and transport the lymph fluid throughout the bird's body.