Photosynthesis energy conversion with

Volkov AG, Gugeshashvili MI, Zelent B et al. Light energy conversion with chlorophyll a and pheophytin a monolayers at the optically transparent Sn02 electrode Artificial photosynthesis. 

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 ... 

Another important metal-containing enzyme, chlorophyll (structure 16.24), is structurally related to myoglobin and is responsible for photosynthesis, the conversion of water and carbon dioxide, with the aid of solar energy, to carbohydrates. 

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. 

After the introduction, we will briefly discuss the main characteristics of solar radiation. Consistent with the scientific principles on which this book is founded, a rigorous thermodynamic analysis will then follow of the creation of wind energy, of photothermal and photovoltaic energy conversion, and of photosynthesis. Most of this chapter has been based on the monograph Thermodynamics of Solar Energy Conversion by De Vos [1]. 

The second article also deals with PET in arranged media, however, this time by discussing comprehensively the various types of heterogeneous devices which may control supramolecular interactions and consequently chemical reactions. Before turning to such applications, photosynthetic model systems, mainly of the triad type, are dealt with in the third contribution. Here, the natural photosynthetic electron transfer process is briefly discussed as far as it is needed as a basis for the main part, namely the description of artificial multicomponent molecules for mimicking photosynthesis. In addition to the goal to learn more about natural photosynthetic energy conversion, these model systems may also have applications, which, for example, lie in the construction of electronic devices at the molecular level. 

Malstrom and Neilands (68). The recent reviews of San Pietro and Black (86) and Arnon (6) are more specifically concerned with ferredoxin in photosynthesis. Also pertinent to the general subject of ferredoxin are the symposia on photosynthesis in higher plants (Photosynthetic Mechanisms of Green Plants (82)) and on the role of non-heme iron proteins in energy conversion (San Pietro (55)). 

Biodiesel to Fuel a Large Power Plant. Researchers at ASU s Center for Bioenergy and Photosynthesis have calculated that a 25 x 25 km field of bioreactors using cyanobacteria to fix carbon could uptake all of the carbon dioxide produced by a 1.6 GW power plant and subsequently provide the biomass as lipid to fuel the power plant. The parameters necessary to achieve this goal are a seven percent power conversion efficiency for photosynthesis, 40 percent conversion efficiency of biomass to fuel, 50 percent conversion efficiency of fuel to electricity, and 80 percent conversion efficiency of land area covered by the bioreactors. This system would then be carbon neutral in operation and produce about 1.6 GW of electrical power. The key to making this feasible is to achieve a seven percent power conversion efficiency for cyanobacteria. Moore noted that the area required to produce a specified amount of energy scales directly with the energy conversion efficiency of the system or device. 

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