Polisakarider

Polisakarider is a general term used to describe polysaccharides, a broad class of carbohydrate polymers composed of long chains of monosaccharide units linked by glycosidic bonds. They vary in sugar composition, linkage patterns, molecular weight, and branching, which gives rise to diverse physical properties and biological roles. Most polisakarider are water-soluble or form gels and can act as energy stores, structural components, or protective materials in living organisms.

Polisakarider are typically classified as homopolysakarider, made from a single type of sugar (for example, starch and glycogen made from glucose, or cellulose and chitin made from glucose derivatives), or heteropolysakarider, composed of multiple monosaccharides (such as pectins, gums, and some hemicelluloses). The specific glycosidic linkages (for example, alpha or beta) and branching determine digestibility, solubility, and mechanical properties.

Biological sources and roles: plants are major producers, storing energy as starch and building structural cellulose; animals and fungi store energy as glycogen; chitin provides exoskeletal support in many arthropods and fungal cell walls. Microbial systems synthesize a wide range of polisakarider for biofilms, protection, and storage.

Applications and relevance: polisakarider are widely used in food industry as thickeners and stabilizers (such as pectin, carrageenan, and xanthan gum), in pharmaceuticals as excipients and hydrogels, and in biodegradable materials and drug-delivery systems. They are also a key component of dietary fiber, influencing digestion and gut microbiota.

See also: polysaccharide, carbohydrate, cellulose, starch, glycogen.

Further reading can be found in standard biochemistry and glycobiology references.