The amino acids that occur naturally as constituents of proteins have an amino group (NH2)(NH2) and a carboxylic acid group (CO2H)(CO2H) attached to the same carbon. They are called α -amino acids...The amino acids that occur naturally as constituents of proteins have an amino group (NH2)(NH2) and a carboxylic acid group (CO2H)(CO2H) attached to the same carbon. They are called α -amino acids and differ only in the nature of the R group on the α carbon and, with few exceptions, they are chiral molecules with the L configuration at the chiral α carbon.
