Carbohydrates are broadly classified into three groups — monosaccharides, oligosaccharides and polysaccharides. Monosaccharides are held together by glycosidic linkages to form disaccharides and polysaccharides. An important monosaccharide glucose was assigned an open chain structure on the basis of its reaction with different reagents, such as $ ext{HI}$, to confirm the presence of a straight chain, and $ ext{H}_2 ext{N}- ext{OH}$ or $ ext{HCN}$ to confirm the presence of a carbonyl group. (a) How do you confirm the presence of straight chain and the presence of a carbonyl group in the open chain structure of glucose ? (b) (i) What are polysaccharides ? OR (b) (ii) How are carbohydrates used as food storage molecules in plants and animals ? (c) Define glycosidic linkage.