FIGURE 2.
Schematic view of the photosynthetic apparatus as a conversion chain. The thick arrows denote the path through which the photon energy is converted into chemical energy stored in ATP via the intermediate stages (rounded rectangles). Each conversion step takes place in proteins that work in parallel. Their number N times the conversion rate of a single protein R determines the total throughput of this step. The microscopic reactions taking place in the RC (denoted by the shaded box), which are here summarized as a single thick arrow, are detailed in Fig. 3. The abbreviations used are γ for the incoming photons collected in the LHCs, E for the excitons in the LHCs and in the RCs, e−H+ for the electron-proton pairs stored on the quinols, e− for the electrons on the Cytochrome c2, ΔpH for the transmembrane proton gradient, and H+ for the protons outside of the vesicle (broken outline of the respective reservoir). Compare this representation to the spatially focused textbook-style view of Fig. 1.