title: Secondary metabolism: raison d'être.
mesh_terms: D000818:Animals; D001419:Bacteria / Q000254:growth & development / Q000378:metabolism*; D005075:Biological Evolution; D002455:Cell Division; D004777:Environment; D056890:Eukaryota / Q000378:metabolism; D005658:Fungi / Q000378:metabolism; D007700:Kinetics