Amino acids are organic compounds that contain both an amino group (-NH2) and a carboxyl group (-COOH). They are the building blocks of proteins, playing important roles in many biological processes. There are 20 common amino acids in nature, each with its own unique structure and properties. These include alanine (Ala), arginine (Arg), asparagine (Asn), aspartic acid (Asp), cysteine (Cys), glutamic acid (Glu), glutamine (Gln), glycine (Gly), histidine (His), isoleucine (Ile), leucine(Leu) , lysine(Lys) , methionine(Met) , phenylalanine(Phe) , proline(Pro) , serin e(Ser ) , threonin e(Thr ) , tryptophan e(Trp ) , tyrosin e(Tyr ) and valin e(Val ).