Polisakkarideja

Polysaccharides are complex carbohydrates composed of long chains of monosaccharide units linked together by glycosidic bonds. These long-chain molecules are essential for many biological processes and serve diverse functions in living organisms. The exact properties and functions of a polysaccharide depend on the type of monosaccharide units present, the length of the polymer chain, and the nature of the glycosidic linkages.

Common examples of polysaccharides include starch, glycogen, cellulose, and chitin. Starch is the primary energy storage polysaccharide in plants, found in grains and tubers. Glycogen serves a similar role in animals, primarily stored in the liver and muscles. Cellulose, a structural polysaccharide, is a major component of plant cell walls, providing rigidity and support. Chitin, another structural polysaccharide, is found in the exoskeletons of insects and crustaceans, as well as in the cell walls of fungi.

These complex carbohydrates can be either linear or branched. The specific arrangement of monosaccharide units and the types of bonds (e.g., alpha or beta glycosidic linkages) dictate whether a polysaccharide is digestible by an organism. For instance, humans can digest starch and glycogen due to the presence of alpha linkages, but cannot digest cellulose, which has beta linkages, due to a lack of the necessary enzymes. Polysaccharides play vital roles in energy storage, structural integrity, and cellular recognition.