1.3.5.5	15,9'-dicis-phytofluene + plastoquinone = 9,15,9'-tricis-zeta-carotene + plastoquinol	(1b)	
1.3.5.5	15-cis-phytoene + 2 plastoquinone = 9,15,9'-tricis-zeta-carotene + 2 plastoquinol	overall reaction	
1.3.5.5	15-cis-phytoene + 2 plastoquinone = 9,15,9'-tricis-zeta-carotene + 2 plastoquinol	overall reaction, ordered ping-pong bi-bi mechanism, both lipophilic substrates are bound inside the same substrate cavity that cannot be occupied by both simultaneously. The central 15-cis configuration of phytoene mediates the regiospecificity in catalysis	
1.3.5.5	15-cis-phytoene + plastoquinone = 15,9'-dicis-phytofluene + plastoquinol	(1a)