In enzymology, a Z-farnesyl diphosphate synthase () is an enzyme that catalyzes the chemical reaction geranyl diphosphate + isopentenyl diphosphate diphosphate + (2Z,6E)-farnesyl diphosphate Thus, the two substrates of this enzyme are geranyl diphosphate and isopentenyl diphosphate, whereas its two products are diphosphate and (2Z,6E)-farnesyl diphosphate. This enzyme belongs to the family of transferases, specifically those transferring aryl or alkyl groups other than methyl groups. The systematic name of this enzyme class is geranyl-diphosphate:isopentenyl-diphosphate geranylcistransferase. This enzyme is also called (Z)-farnesyl diphosphate synthase. References EC 2.5.1 Enzymes of unknown structure