Final answer:
Starch is made up of two polymers, amylose and amylopectin. Amylose is a linear polysaccharide that forms a helical structure and can interact with water molecules through hydrogen bonding. It can accommodate an iodine molecule, giving a characteristic blue-violet color when treated with iodine.
Step-by-step explanation:
Starch is a mixture of two polymers, amylose and amylopectin. Amylose is a linear polysaccharide composed of glucose units joined by a-1,4-glycosidic linkages. When coiled, amylose can accommodate an iodine molecule, giving the characteristic blue-violet color when treated with iodine. Water molecules can interact with the -OH groups on the helical amylose structure through hydrogen bonding.