What Are Polysaccharides

Polysaccharides consist of a large number of monosaccharide units joined together by gty cosidic bonds. Three important polysaccharides, all made up of glucose units, are starch, glycogen, and cellulose. 

Starch is found in all plant seeds and tubers and is the form in which glucose is stored for later use. Starch can be separated into two principal polysaccharides amylose and amylopectin. Although the starch from each plant is unique, most starches contain 20 to 25% amylose and 75 to 80% amylopectin. 

Cellulose, the most widely distributed plant skeletal polysaccharide, constitutes almost half of the cell-wall material of wood. Cotton is almost pure cellulose. 

Both rayon and acetate rayon are made from chemically modified cellulose and were the first commercially important synthetic textile fibers. In the production of rayon, cellulose fibers are treated with carbon disulfide, CSg, in aqueous sodium hydroxide. In this reaction, some of the —OH groups on a ceUulose fiber are converted to the sodium 

Cellulose is a linear polymer of D-glucose, joined by /3-1,4-glycosidic bonds. 

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