title: Analytical model of ion transport and conversion of light energy in chloroplasts.
abstract: An analytical model, which describes the stationary transformation of light energy to the energy of pigment electronic excitation, has been constructed. A proton pump of the thylakoid membrane has been considered as a two-level conformon. The difference between the energies of the excited and ground states of both the pigment and the protein complex is assumed to be the energy of an absorbed photon. It has been found how the concentration of ions in a lumen and the potential across the thylakoid membrane depend on the concentration of ions in the stroma and the brightness temperature of absorbed radiation. Conditions for the maximum efficiency of the photosynthesis process have been analyzed. This model has been used to determine the electric potential (phi approximately 6.7mV) at the chloroplast thylakoid membrane. The calculated value of the electric potential is in good agreement with the experimental data. A limitation on the stoichiometric coefficient of the proton transport through ATP-synthase, m>3, has been found theoretically.
authors.affiliation: Ural State Technical University, 19 Mira St, 620002 Ekaterinburg, Russia. melkikh2008@rambler.ru
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Melkikh
authors.forename: Vladimir D
authors.initials: VD
authors.lastname: Seleznev
authors.forename: Oksana I
authors.initials: OI
authors.lastname: Chesnokova
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis; D002736:Chloroplasts / Q000378:metabolism* / Q000528:radiation effects; D004579:Electron Transport; D004734:Energy Metabolism / Q000502:physiology*; D017136:Ion Transport; D008027:Light; D008954:Models, Biological; D010788:Photosynthesis / Q000502:physiology / Q000528:radiation effects; D045331:Photosystem I Protein Complex / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D013816:Thermodynamics; D020524:Thylakoids / Q000378:metabolism / Q000528:radiation effects
chemical_list: D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D000255:Adenosine Triphosphate