Amino acids are class of organic molecules which contains a carboxyl group( COOH), an amine group(NH2) and a R group( hydrocarbon side chain ). The central Carbon atom in any amino acid is called as Cα. It is Cα to which COOH, NH2 and R attach. The side chain R may contain other elements too. Amino acids differ from each other on the basis of side chain.
About 500 amino acids have been discovered but only 20 are known to be part of genetic code. These 20 amino acids are translated from respective codons and then they come together to form polypeptide chains. Hence, amino acids are building blocks of proteins.
