Fig. 7
Conceptual model of phototrophic extracellular electron uptake. Extracellular electron uptake is connected to the photosynthetic electron transport chain (pETC) and carbon dioxide (CO2) fixation in R. palustris TIE-1. The CBB cycle (Calvin-Benson-Bassham) uses RuBisCO and is the primary sink for electrons that enter the photosystem from poised electrodes. The electrons are used by the CBB cycle as NAD(P)H (reduced nicotinamide adenine dinucleotide phosphate) that is exchanged with NADH (reduced nicotinamide adenine dinucleotide) produced via reverse electron flow. For details please read the text. ATP (adenosine triphosphate), e− (electrons), P870 (photosystem), P870* (excited photosystem), UQ (ubiquinone), bc1 (cytochrome bc1), c2 (cytochrome c2), H+ (protons), hv (light), ? (currently unknown), OM (outer membrane), P (periplasm), CM (cytoplasmic membrane) and ICM (inner cytoplasmic membrane)
