Aminoaciduria is the presence of amino acids in the urine. Small amounts of amino acids are also present in normal urine. Increased total urine amino acids may result from metabolic disorders, chronic liver disease or renal disorders. An amino acid residue is what is left of an amino acid once a molecule of water has been lost (an H+ from the nitrogenous side and an OH- from the carboxylic side) in the formation of a peptide bond. ... Urine is liquid waste excreted by the kidneys and is produced by the process of filtration. ... A metabolic disorder is a medical disorder which affects the production of energy within individual human (or animal) cells. ...