All tissues have some capability for synthesis of the non-essential amino acid remodeling, amino acids and conversion of non-amino acid carbon skeletons into amino acids and other derivatives which holds nitrogen. Furthermore, the liver is the main site of nitrogen metabolism in the body. In the times of dietary extra the potentially toxic nitrogen of amino acids is eliminated by deamination, transaminations, and urea formation; the carbon skeletons are generally conserved as carbohydrate, through gluconeogenesis, or as fatty acid by fatty acid synthesis pathways.