Proteins (Definition Structure,Classification and Function) Proteins Proteins are the most functionally molecules of the biological system. The term protein is derived from Greak word Proteeious means first. The name of protein was suggested by a scientist Berzelins in 1838. Protein are the organic compounds,compose of carbon,oxygen,hydrogen, nitrogen,sulphur and some time phosphorous. They occur in every part of cell and constitute about 50% of the dry weight of cell. Proteins are formed from amino acids joined in the form of a chain. Amino acids are a group of organic compounds containing two functional group amino and carboxyl. The amino group (-NH2) is basic while Carboxyl group (-COOH) is acidic in nature. They are made up of 20 standard amino acids. Structure of protein According to structure there are four types: 1.Primary structure When amino acids are arranged in linear manner in a polypeptide chain,it is called primary structure. SECONDARY Structure: When ami...