Polizaharid

Polizaharid is a high-molecular-weight carbohydrate polymer composed of monosaccharide units linked by glycosidic bonds. They are among the most abundant biopolymers in nature and serve a range of biological roles, including energy storage, structural support, and protection.

Polysaccharides are classified as homopolysaccharides (containing a single type of sugar) or heteropolysaccharides (two or more sugars). They can be linear or branched. Common examples include starch and glycogen (energy storage, glucose units); cellulose and chitin (structural; beta linkages); and heteropolysaccharides such as pectin, hemicelluloses, and gums (agar, carrageenan) that contribute to plant cell walls and mucilage.

In plants and animals, digestion depends on the linkages and available enzymes. Alpha-linkages in starch and glycogen are digestible by specific enzymes (amylases), providing calories. Beta-linkages in cellulose are not digested by human enzymes but can be fermented by gut microbiota; many polysaccharides also function as dietary fiber with health benefits such as improved gut transit and fermentation products.

Industrial and culinary uses are widespread, including thickening, gelling, and stabilizing foods; excipients in pharmaceuticals; and various applications in biotechnology and materials science. The term polizaharid is used in some languages to refer to polysaccharides in general, encompassing a broad range of structurally diverse carbohydrate polymers.