If we take the dry mass of any cell that exists on the earth we will mainly end up with four essential class of molecules. These four essential molecules are classified as proteins, nucleic acids, carbohydrates and lipids. They provide structure and energy to the cells of all living organisms. In addition, these molecules are necessary for the various functions in cells, therefore, they are referred to as fundamental molecules of life. Proteins are essential molecules for the existence of life and are the most abundant molecules found in all living organisms. They account for ~50% of the dry weight of any cell. The key role of proteins in cells is to provide structure and to be involved in the various cellular functions such as muscle formation, transport, transfer of information, catalysts and much more, for this reason they are also recognized as building blocks of life. The fundamental unit of the primary structure of a protein is called amin...