all-trans-zeta-carotene + 2 A = all-trans-lycopene + 2 AH2
all-trans-zeta-carotene + 2 a = all-trans-lycopene + 2 ah2
all-trans-zeta-carotene + 2 A = all-trans-lycopene + 2 AH2
all-trans-zeta-carotene + 2 a = all-trans-lycopene + 2 ah2