Light-Harvesting Pigments in Photosynthetic Bacteria

The major pigments of photosynthetic organisms occur in two functionally different roles in the photon-converting membranes. The major portion (typically up to 99% or more) serve as light-harvesting pigments to absorb the incident radiation and transfer the resulting electronic excitation to photosynthetic reaction centers. There, the second portion of the chlorophylls play an essential role in initiating the primary electron transfer. All of these pigments are thought to exist in specific complexes with proteins in the photosynthetic membranes. These pigments in the photosynthetic bacteria, Rhodopseudomonas sphaeroides, are briefly discussed in this paper. (JMT)