Polysaccharides shape when monosaccharides or disaccharides arrange in chains. They are carbohydrate structures and generally classify as heterogeneous. They are mostly occurs in plants and are utilized as food and energy storage by most animals.
When they are formed by the same repeating structures of monosaccharides, they are now called homo polysaccharides such as starch, glycogen and cellulose, formed each of them by thousands of molecules of glucose attached by glycosidic linkages.
If the polysaccharides molecules are formed by different chains of monosaccharides, they are now called hetero polysaccharides. Hyaluronic acid, formed by hundreds of replacement units of N-acetyl glucosamine and glucuronic acid, are the examples of heteropolysaccharide.
Cellulose is a linear based polymer of D-glucose residues linked by b(1, 4)-O-glycosidic linkages. It is the most existing carbohydrate in nature.
It is formed by glucose sites, bonded by Beta-1, 4 O-glycosidic linkages. We can say then that, if we take the kind of linkage, the repeating site in cellulose is cellobiose, the disaccharide formed by a couple of molecules of glucose linked by Beta-D-O glycosidic bonds.
The thin fibers of cellulose are tied together by strong hydrogen bonds. Hydrogen bonding goes in the same plane with other chains, and this plane results to form a strong, fibrous bundles. It made cellulose, very suitable for its inter-structural function in plants.
Since cellulose is made by glucose molecules, it can be a good source of packet energy for most of species. The lack in human beings of useful enzymes for digesting cellulose make this polysaccharide unstable for human nutrition.
Starch is the second most abundant carbohydrate after the Cellulose.
The biological functions involves, in plants, the better way of storage of sugar, and consequently, of energetic resources; in humans, the very first supply of glucose on diet.
Starch is not actually a molecule, but a grain established by two vary kinds of molecules, i.e. Amylose and Amylopectin.
Amylose is a linear based molecule established by different glucose units bonded by alpha-1, 4 O glycosidic linkages. Taking in account the complex sorts of linkage, we can say that the repeating unit in amylose is maltose, as per to some sources.
Amylopectin is the also a kind of molecule that makes starch. It is a long branched molecule, formed also by glucose. Amylopectin constitutes D-glucose residues linked together by a(1, 4)-O-glycosidic linkages, with branching via a (1 6)-O-glycosidic linkages. The disaccharides that can be acquired from the digestion of amylopectin are maltose and also the isomaltose.
The structure of glycogen is very much same to amylopectin but more branched, with almost one branch every 8 to 12 glucose site.
Glycogen is the way same in which glucose is stored in animals. Glycogen is stored in liver and also in muscle, where it is utilized as a reserve of energy for muscular constriction.
Chitin is another example; it is the light substance that makes crustacean and clam shells, as well as insect exoskeletons. Chitin is not very much easily broken down and is very usual, and so hits as protection in organisms and composes lots of industrial uses.
It is a strong anticoagulant secreted in the Mast Cells that results antithrombin bind to thrombin and feels inhibition of blood coagulation.
Glycosaminoglycans are synthesized in both the ER and Golgi. They are devalued by lysosomal hydrolases. A lankness of one of the hydrolases can causes in a form of mucopolysaccharidosis. These are basically a hereditary disease in which glycosaminoglycans cumulate in tissues, causing hilarious symptoms like, skeletal and extracellular matrix deformities etc.