ornithine metabolic process L-ornithine biosynthetic process https://github.com/geneontology/go-ontology/issues/28527 https://github.com/geneontology/go-ontology/issues/31510 ornithine biosynthetic process MetaCyc:ARGININE-SYN4-PWY The chemical reactions and pathways resulting in the formation of 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. ornithine anabolism MetaCyc:GLUTORN-PWY MetaCyc:PWY-6922 ornithine synthesis ornithine biosynthesis biological_process GO:0006592 ornithine formation amino acid biosynthetic process non-proteinogenic amino acid biosynthetic process