regulates regulates regulation of amino acid metabolic process ornithine metabolic process regulation of small molecule metabolic process biological regulation regulation of ornithine metabolic process biological_process Any process that modulates the rate, frequency, or extent of the chemical reactions and pathways involving ornithine, an amino acid only rarely found in proteins, but which is important in living organisms as an intermediate in the reactions of the urea cycle and in arginine biosynthesis. GO:0090368 2010-07-12T11:14:12Z tb