INTRODUCTION

1.3. Protein

Living systems are made up of Proteins which are the dehydration polymers of amino acids.

Composition: Carbon, hydrogen, oxygen, nitrogen, and sometimes sulphur.

 Each amino acid residue is joined by a peptide linkage to form proteins. 

Proteins are the molecular instruments in which genetic information is expressed, Hormones, Antibodies, transporters, the lens protein, the architectural framework of our tissues and a myriad of substances having distinct biological activities are derived. 

The type, nature and number of amino acids impart characteristic properties to the proteins. 

 There are about 300 amino acids, but only 20 are coded by DNA of higher organisms. 

The structural organization of proteins could be primary, secondary, tertiary and quaternary. 

The three dimensional structure is the most biologically active one. In addition, the unfolding and disorganization of the proteins results in denaturation, the process is mostly irreversible. Such a protein may lose its biological function.