ABSTRACT
This chapter aims to understand the general structure of amino acid, and examines special functions of amino acids and structural relationships between amino acids. The name amino acid suggests that the structures have an amine and an acid group. Indeed this is true; amino acids have an amino group and a carboxylic acid. The most important reaction amino acids can undertake is the formation of an amide bond. This forms between an amine group and an acid group and water is removed. An amide bond formed between 2 amino acids is given a special name – a peptide bond. Proteins and peptides are formed from a string of amino acids linked together by amide bonds. Some people lack phenylalanine hydroxylase and cannot make tyrosine. They therefore end up with an excess of phenylalanine which is excreted into the urine after being modified into a ketone.
