Starch
Starch , common name applied to a white, granular or powdery, odorless, tasteless, complex carbohydrate, (C 6 H 10 O 5 ) x , abundant in the seeds of cereal plants and in bulbs and tubers. Molecules of starch are made of hundreds or thousands of atoms, corresponding to values of x, as given in the formula above, that range from about 50 to many thousands. Starch molecules are of two kinds. In the first kind, amylose, which constitutes about 20 percent of ordinary starch, the C 6 H 10 O 5 groups are arranged in a continuous but curled chain somewhat like a coil of rope; in the second kind, amylopectin, considerable side-branching of the molecule occurs. Starch is manufactured by green plants during the process of photosynthesis . It forms part of the cell walls in plants, constitutes part of rigid plant fibers, and serves as a kind of energy storage for plants, because its oxidation to carbon dioxide and water releases energy. The granules of starch present in any...