ABSTRACT
The twenty L-amino acids are of central biological importance as they provide the building blocks of proteins. Considering this importance, it is perhaps surprising that mammals can synthesize only ten amino acids by de novo pathways. The remainder must be supplemented in their diet. This leads to significant nutritional problems to the human population of many regions of the world. Higher plants and many bacteria possess the ability for de novo synthesis of all protein amino acids. Details of the amino acid biosynthetic pathways can be found in any good biochemistry text.
