Energy Conversion - Photosynthesis

In a more realistic model, photoenergically driven ATP synthesis was mimicked by the system described in Fig. 6.9. The triad carotene-porphyrin- 

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Energy Conversion - Photosynthesis During the process of photosynthesis, a well-organized dye array in the cell membrane accomplishes pho-toinduced charge separation that eventually leads to ATP synthesis. This system has been mimicked by immobilizing a fimctional dye molecule and ATP synthase in a lipid bilayer membrane. 

This is the present state in the development of chemical systems for artificial photosynthesis. For solar energy conversion and... 

Several researchers have considered photosynthesis in nature as a model for electrochemical conversion of sunlight to chemical energy [8]. Photosynthesis is discussed in several textbooks [37-40]. The topic of photosynthesis and photoelectrochemistry is discussed in Section 7.5. 

Ganguly, T. Pal, S. K. 2006. Photoinduced electron transfer research to build model compounds of artificial photosynthesis and solar energy conversion. J. Chinese Chem. Soc. 53 219-226. 

There have been many attempts to mimic some features of photosynthesis with abiotic systems for purposes of artificial solar energy conversion. Ideally a fuel, e.g., H2, is formed through a photosynthetic process. Photolysis of water is a highly endergonic process ... 

Govindjee (ed) (1982) Photosynthesis Energy conversion by plants and bacteria. Academic Press, New York... 

Gest H. 1972. Energy conversion and generation of reducing power in bacterial photosynthesis. Adv Microb Physiol 7 243-82. 

Another important phytotoxic atmospheric pollutant that has been studied with respect to its inhibitory effects on plant photosynthesis is peroxyacetyl nitrate (PAN). This phytotoxicant applied for 30 min at 1 ppm depressed the incorporation of 1 C02 into intact pinto bean leaves, but only after visible tissue injury started to develop (20). From companion studies on isolated chloroplasts, it was concluded that PAN-induced inhibition was probably associated with the carboxylating reaction or the chloroplast light-energy conversion system leading to assimilative power. The inhibition appeared to result in a quantitative reduction (but not a qualitative change) in the early products of photosynthesis. 

The inverted region was initially predicted by Marcus and the decrease in the electron transfer rate constant with —AG° has been observed experimentally many times.18 This is an important and remarkable result both for natural and artificial photosynthesis and energy conversion it predicts that, following electron transfer quenching of the excited A -B, the back electron transfer in the inverted region for the charge-separated state A + -B becomes slower as the energy stored increases. 

Apart from the possible use of polymerized vesicles as stable models for biomembranes (Sect. 4) there may be a variety of different applications. Polymerized surfactant vesicles have been proposed to act as antitumor agents on a cellular level33 in analogy to the action of the immune system of mammals against tumor cells 85). Polymerized vesicles open the door to chemical membrane dissymmetry 22) which in turn, may lead to enhanced utility in photochemical energy transfer84 (solar energy conversion, artificial photosynthesis). The utilization of unpolymerized lipo-... 

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