Photosynthesis photosynthetic unit

Photosynthetic activity, measured as uptake of carbon dioxide, depended on the leaf area. Gibberellic acid did not influence photosynthesis per unit... 

A better understanding of the photosynthetic units of the in vivo system are essential for both the in vitro and in vivo approaches but if one is looking for practical applications the emphasis of the work changes from one approach to the other. If one is to modify photosynthesis in vivo one is almost certainly going to use the methods of genetic engineering so that immediately one needs to know the specific protein complexes involved, their sequences and those of their genomes. 

In conclusion the molecules l(n) consitute a series of model systems that not only provides donor-acceptor separations similar to those found in the photosynthetic unit, but also mimics the high rate and the temperature independence of the primary steps in photosynthesis. 

Wild, A., and Ball, R. 1997. Photosynthetic Unit and Photosynthesis. Backhuys, Leiden, The Netherlands. 

Nonetheless, photosynthesis did not evolve immediately at the origin of life. The failure to discover photosynthesis in the domain of Archaea implies that photosynthesis evolved exclusively in the domain of Bacteria. Eukaryotes appropriated through endosymbiosis the basic photosynthetic units that were the products of bacterial evolution. All domains of life do have electron-transport chains in common, however. As we have seen, components such as the ubiquinone-cytochrome c oxidoreductase and cytochrome hf family are present in both respiratory and photosynthetic electron-transport chains. These components were the foundations on which light-energy-capturing systems evolved. 

Strasser, R.J. The grouping model of plant photosynthesis Heterogeneity of photosynthetic units in thylakoids. in Photosynthesis III. Structure and function of the photosynthetic apparatus (G. Akoyunoglou, ed.), Balaban, Philadelphia, 1981. 

T p y+l)/k0j, where k j is the RC trapping rate and V is the ratio of the probabilities of finding the exciton in the antenna system and RC. It can be shown that from nine experimental observables (fluorescence and phosphorescence intensities and quantum yields, 7) qj) only one is independent. In all the transfer regimes, the observables depend only on V which is in general a function of time, intramolecular rate constants, size of the photosynthetic unit and initial conditions. Therefore, V (t) is the maximum information obtainable from the observables. These and further results representing general theoretical answers to problems l)-5) were illustrated on the case of the bacterial photosynthesis (Rhodopseudomonas viridis) where they are valid for the whole range of the physically acceptable values of the Forster radius. 

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