<span>After
digestion, an amino acid not absorbed by the body and not used to build
proteins will first be subjected to removal from its amino group. If they are
not used for protein synthesis, amino acids becomes part of the metabolism
process. The body has the capability to create a subset of amino acids, also
known as non-essential amino acids because we don’t have requirement for them
in our diet. </span>
LeveneChargaffWatson and CrickNirenberg and Matthaei
