The light-dependent and light-independent reduction of protochlorophyllidea to chlorophyllide a

Two different pathways for protochlorophyllide a (Pchlide) reduction in pho tosynthetic organisms have been proved: one is strictly light-dependent whe reas the second is light-independent. Both pathways occur in all photosynth etic cells except in angiosperms which form chlorophyll only through the li ght-dependent pathway. Most cells belonging to Eubacteria (i.e., the anoxyg enic photosynthetic bacteria) synthesize bacteriochlorophyll through the li ght-independent pathway. This review deals with the physiological, biochemi cal, and molecular biological features of molecules involved in both pathwa ys of Pchlide reduction.