Question

Give the general formula of monosaccharides and polysaccharides.
A.$$(C{H}_{2}O{)}_n,C_n(H_{2}O{)}_{2n}$$
B.$$(C{H}_{2}O{)}_{2n},C_n(H_{2}O{)}_n$$
C.$$(C{H}_{2}O{)}_n,C_n(H_{2}O{)}_{n-1}$$
D.$$(C{H}_{2}O{)}_{n-1},C_n(H_{2}O{)}_{n-1}$$

Answer 1

Hint: Carbohydrates are one of the four major macromolecules necessary for human beings. They are found in the form of sugar and starch in our body. Carbohydrates are generally categorised into three groups which are monosaccharides, disaccharides and polysaccharides.

Complete answer:
According to chemistry Carbohydrates are defined as the molecules or substances that give polyhydroxy aldehyde or polyhydroxy ketones on hydrolysis. Let us discuss the types of carbohydrates.
Monosaccharides: Monosaccharides are simple molecules which cannot be hydrolysed into simpler molecules. The general formula for monosaccharides is given as $$(C{H}_{2}O{)}_n$$. Some examples of monosaccharides are Glucose, Fructose and Galactose.
Disaccharides: Disaccharides are formed by connecting two monosaccharides through a special bond or linkage known as glycosidic linkage. The general formula for the disaccharides is given as $$C_n(H_{2}O{)}_{n-1}$$. Some examples of disaccharides are Maltose, Sucrose and Lactose.
Polysaccharides: Most of the carbohydrates that are found in nature exist as polysaccharides. They have very high molecular weights. Polysaccharides are complex molecules that are formed by the process of polymerisation. Large number of monosaccharides undergo polymerisation to form polysaccharides. The general formula for the polysaccharides is given as $$C_n(H_{2}O{)}_{n-1}$$. Some examples of polysaccharides are Cellulose and Starch.
From the above information we found that general formula for monosaccharides and polysaccharides are $$(C{H}_{2}O{)}_n$$ and $$C_n(H_{2}O{)}_{n-1}$$ respectively.

So, option (C) is the right answer.

Note:
Polysaccharides are large chain molecules that may be branched or unbranched. On hydrolysis polysaccharides produce monosaccharide derivatives or large numbers of monosaccharides. Polysaccharides are used to store energy in our body, they also help in growth of the cells.