Photoautotroph: Algae, Cyanobacteria CO2+H20 Light Chlorophyll(CH20)+O2 Purple and green bacteria CO2+2H2S Light+ bacteriochlorophyll,(CH20)+ H2O+2S Photoheterotroph: Purple nonsulfur bacteria( rhodospirillum) CO2+2CH3CHOHCH3 Light bacteriochlorophyll(CH2O) +H2o+ 2CH3 cocH3Algae, Cyanobacteria CO2 + H2O Light + Chlorophyll （CH2O） +O2 Purple and green bacteria CO2 + 2H2S Light + bacteriochlorophyll（CH2O） + H2O + 2S Purple nonsulfur bacteria (Rhodospirillum) CO2 + 2CH3CHOHCH3 Light + bacteriochlorophyll（CH2O） + H2O + 2CH3COCH3 Photoautotroph: Photoheterotroph: