In enzymology, chlorophyll synthase () is an enzyme that catalyzes the chemical reaction chlorophyllide a + phytyl diphosphate chlorophyll a + diphosphate The two substrates of this enzyme are chlorophyllide a and phytyl diphosphate; its two products are chlorophyll a and diphosphate. The same enzyme can act on chlorophyllide b to form chlorophyll b and similarly for chlorophyll d and f. Chlorophyllide a.svg|Chlorophyllide ''a'' Chlorophyll a structure.svg|Chlorophyll ''a'' 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 chlorophyllide-a:phytyl-diphosphate phytyltransferase. This reaction is the final step of the complete biosynthetic pathway to chlorophylls from glutamic acid.