Q.Classify the following into monosaccharides, oligosaccharides and polysaccharides.

Classification of Carbohydrates

Carbohydrates are polyhydroxy aldehydes/ketones (or compounds that yield them on hydrolysis). They are classified by the number of simple-sugar units released on hydrolysis:

• Monosaccharides — cannot be hydrolysed further, e.g. glucose, fructose, ribose, rhamnose. Glucose reacting with HI on prolonged heating gives n-hexane, proving its straight six-carbon chain.
• Oligosaccharides (2–10 units), chiefly disaccharides such as sucrose, maltose and lactose, which hydrolyse to their monosaccharides. Concentrated $\mathrm{H_2SO_4}$ dehydrates sucrose completely to a black mass of carbon.
• Polysaccharides — many units linked by glycosidic bonds; these are non-sweet, usually water-insoluble storage/structural molecules. Starch is a mixture of linear amylose (α-1,4 linkages, ~15–20 %, water-soluble) and branched amylopectin (α-1,4 and α-1,6). Glycogen is a highly branched animal storage polysaccharide, and cellulose is a linear β-1,4 structural polymer. …