starch

the form in which CARBOHYDRATES are stored in many plants and a major constituent of the diet. Starch consists of linked glucose units and occurs in two forms, a-amylose and amylopectin. In a-amylose the units are in the form of a long unbranched chain; in amylopectin they form a branched chain. The presence of starch can be detected using iodine: a-amylose gives a blue colour with iodine; amylopectin a red colour. Starch is digested by means of the enzyme AMYLASE .