11.2.1.2 Oligosaccharides
Carbohydrates that produce two to ten monosaccharide units during the hydrolysis are called oligosaccharides. They can be further classified based on the number of monosaccharide units formed on hydrolysis.
Disaccharides: They give two monosaccharide units on hydrolysis, which may be the same or different. For example, sucrose on hydrolysis gives one molecule each of glucose and fructose, whereas maltose gives two molecules of glucose (Scheme 1).
Scheme 2
Trisaccharides: These carbohydrates yield three molecules of monosaccharides units on hydrolysis (Scheme 2).
Scheme 3
11.2.1.3 Polysaccharides
These carbohydrates give a large number of monosaccharide units on hydrolysis. These monosaccharide units are joined together by oxide bridges. These linkages are called glycosidic linkages. The common and widely distributed polysaccharides correspond to the general formula (C6H10O5)n . Polysaccharides are not sweet in taste, so they are called non-sugars. Some common examples are starch, cellulose, glycogen, etc (Scheme 3).
Scheme 3