Question

Give 2 examples of each of the following and their usefulness, if any, in our body:
(i) monosaccharides
(ii) Disaccharides
(iii) polysaccharides

Answer 1

Monosaccharides are simple sugars with one water molecule attached to the carbon molecule. Disaccharides are the sugars formed when 2 simple sugars are joined by glycosidic linkage. polysaccharides are long chains of monosaccharides joined by the glycosidic linkage.

Complete answer:
I. The main examples of monosaccharides are simple sugars like glucose, fructose, xylose, ribulose, etc. they act as energy storehouses in the body and as basic building blocks of higher complex sugars.
II. Disaccharides are the sugars such as sucrose, lactose, maltose, etc. They are often found in food as a sweetener. Lactose is present in breast milk and provides nutrition to the infant.
III. Examples of polysaccharides are cellulose and glycogen. They act as short term energy storage in plant cells. They help in the communication of cells with one another. They also help in cellular support.

Additional Information:
1. Both disaccharides and polysaccharides are reducing sugars
2. Both monosaccharides and disaccharides are soluble in water
3. Disaccharides are derived from the sweet root vegetables, from sugar cane, sugar beet, etc
4. Polysaccharides are reducing sugars which can be identified using Benedict's test.
5. Major disaccharides are maltose, lactose, and sucrose.
6. Sucrose is naturally obtained from plants and later table sugar is obtained from it.
7.It stores energy in various plants and also helps in the transportation of the nutrients.

Note: Saccharides are simple sugars that are linked by glycosidic linkage. They are composed of carbon, hydrogen, and oxygen and exist in a ring structure. They, as observed typically, are 5 or 6 carbon ring structures.