all-trans-beta-carotene + O2 <=> 2 all-trans-retinal
all-trans-beta-carotene + o2 <=> 2 all-trans-retinal
all-trans-beta-carotene + O2 <=> 2 all-trans-retinal
all-trans-beta-carotene + o2 <=> 2 all-trans-retinal