Define the following terms:

(i) Polysaccharides

(ii) Amino acids

(iii) Enzymes

(i) When many monosaccharide units are linked through glycosidic bonds, to form polymeric chains are called polysaccharides. They are also called complex sugars. Eg., starch, cellulose.

(ii) Amino acids are organic compounds consisting of both amine(-NH₂) and carboxylic acid(-COOH) groups and are essential for basic functions of an organism are called amino acids. They are the building blocks of proteins.

(iii) Enzymes are protein molecules in cells which enhance the speed of a reaction but are not consumed in the reaction(work as catalysts). They are vital for all biological activities in an organism.