What is the source of free animo acids in the cytoplasm

Most of the amino acids found free in the cytoplasm come from diet. Various amino acids are present in the pool of the cytoplasm which include both essential and non-essential amino acids. Essential amino acids are those that cannot be made by the body and must be obtained from food. Non-essential amino acids are those which the body can make on its own. In the cytoplasm, the essential amino acids found in highest concentration are lysine, threonine, valine and leucine while of the non-essential, glutamine, glycine and alanine are found in higher concentration.