Starch is a natural polysaccharide and the primary carbohydrate storage molecule in plants, consisting of two glucose polymers: amylose (linear α-1,4 linkages) and amylopectin (branched with α-1,6 linkages). It serves as an energy reserve in seeds, roots, and tubers. In food science, starch acts as a thickener, stabilizer, and gelling agent when heated in water, undergoing gelatinization. It is widely used in cooking, baking, and industrial applications. Chemically inert under normal conditions, it hydrolyzes to glucose via enzymes or acid. Native starch granules are semicrystalline and insoluble in cold water but swell and disperse upon heating. It is biodegradable and renewable.