Polysaccharides generally called glycans, are compounds formed by the condensation of a number of monosaccharide units linked through glycosidic bonds. They serve as structural components of the cell as well as function as nutrients. They can be hydrolyzed by acids or enzymes to yield monosaccharides or their derivative. Most common polysaccharides are starch, inulin, amylopectin, glycogen, and mannans. In chemical terms polysaccharides may be divided into two broad group :
1.Homopolysaccharides or homoglycans which yield only one type of monomer units upon hydrolysis, viz. cellulose, glycogen and starch.
2. Heteropolysaccharides or heteroglycans that yield two or more types of monomer units viz. hyaluronic acid, chondriotin  sulphate, heparin and mureins.

It is the most common and abundantly occurring polymer of D-glucose units found in the cell wall of plants, usually associated with lignin. The bonds holding glucose units are β-1, 4, glycosidic linkages. Strong HCI hydrolyzes cellulose into its constituent glucose monomers, but mild hydrolysis yields disaccharide fragments of cellobiose.

Glycogen is a storage polysaccharide found in many animal tissues such as liver and muscle. It is a branched polymer having about 8 to 10 glucose units in each branch. Straight chains of glycogen are held by α-1,4 glycosidic linkages and the branches are linked to the main chain by α-1,6 glycosidic bonds. thus in chemical structure it is similar to that of amylopectin except that is more highly branched.

Mannans

Mannans are linear polysaccharides found in cell walls of bacteria, yeasts and some higher plants. They are composed of mannose units and the bonds involved are α-1,2 and α-1,3 glycosidic bonds. In some cases branched mannans are also found.

Hyaluronic Acid