excess and unused amino acids of the body are stored in the liver. In the de-amination process, keto acids and NH2 are formed from excess amino acids by the action of deaminase enzymes. NH2 produces toxic ammonia. Ammonia and CO2 react through the ornithine cycle to produce urea. The urea produced stays in the plasma and then reaches the kidneys. Excreted out of the body through the creation of urine.