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TESTING KINETIC MODELS FOR THE BACTERIORHODOPSIN PHOTOCYCLE—II. INCLUSION OF AN O TO M BACKREACTION 总被引:4,自引:0,他引:4
Luis A. Parodi Richard H. Lozier Somendra M. Bhattacharjee John F. Nagle 《Photochemistry and photobiology》1984,40(4):501-506
Abstract Using previously established procedures we have tested a kinetic model of bacteriorhodopsin involving a backreaction from O to M. This model is superior to the previously tested models involving only unidirectional reaction paths. However, the spectrum of O is still too strongly temperature dependent in the red. Therefore, at least one additional feature is necessary to obtain a completely consistent kinetic model of the bacteriorhodopsin photocycle. 相似文献
294.
Seth D Chakraborty A Setua P Chakrabarty D Sarkar N 《The journal of physical chemistry. B》2005,109(24):12080-12085
The energy transfer using 7-amino coumarin dyes as the donor and rhodamine 590 (Rh6G) as the acceptor was investigated in lecithin vesicles and sodium taurocholate (NaTC)-lecithin mixed aggregates using steady-state and time-resolved fluorescence spectroscopy. All energy transfer parameters were calculated. The coumarin 153-Rh6G pair is the most efficient donor-acceptor pair as reflected by the value of k(ET). With addition of NaTC in lecithin, in the case of the coumarin 153-Rh6G pair, the energy transfer rate or efficiency does not change very much, whereas in the case of the coumarin 151-Rh6G pair, the energy transfer rate decreases 2-fold upon going from lecithin vesicles to NaTC-lecithin mixed aggregates where the molar ratio is 2.5. It is mainly due to the deeper location of coumarin 153 in the lipid bilayer or in mixed aggregates. Rotational relaxation data also support this idea. 相似文献
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Oxidative Cleavage of S–S Bond During the Reduction of Tris(pyridine‐2‐carboxylato)manganese(III) by Dithionite in Sodium Picolinate–Picolinic Acid Buffer Medium 下载免费PDF全文
The reduction of tris(pyridine‐2‐carboxylato)manganese(III) by dithionite has been investigated within the temperature window 288–303 K and at pH range 5.22–6.10 in sodium picolinate–picolinic acid buffer medium. The reaction obeys the following stoichiometry: The reaction is described in terms of a mechanism that involves an initial complex formation between S2O42? and [MnIII(C5H4NCO2)3] followed by S–S bond cleavage to give 2HSO3? and [MnII(C5H4NCO2)2(H2O)2] as the products via the formation of SO2●? radical anion. Kinetics and spectrophotometric evidences are cited in favor of the suggested mechanism. Thermodynamic parameters associated with the equilibrium step and the activation parameters with the rate‐determining step have been computed. 相似文献
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In the present study, the optical properties of the 7.O5O.7 dimeric compound are reported. This dimeric compound exhibits typical smectic A to smectic F phase transition, and the main focus of our study is to observe the optical behaviour in SmA phase. In the dimeric compound, the two mesogens are connected by a linkage group or spacer. The presence of the linkage group and the terminal alkyl chains plays a vital role to change the behaviour of this compound as compared to the traditional monomeric compounds. Study of birefringence, refractive indices and normalised polarisation are essential to investigate the optical nature in liquid crystalline compounds. The optical study in our compound is carried out by using the thin prism experimental method with the help of He-Ne laser of wavelength 633 nm. Four-parameter model was used to obtained theoretically measured refractive indices and birefringence data. The theoretical results are then compared with the experimental results. Both the experimentally and theoretically calculated results are properly fitted in our dimeric compound. 相似文献
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Imidazole type ionic liquid, 1‐hexadecyl‐3‐methylimidazolium chloride, was used to template the synthesis of high‐surface‐area mesoporous silica under acidic conditions and crystalline titanium dioxide (TiO2) nanoparticles of anatase phase were inserted utilizing a solvent evaporation‐induced method. The surface area of more than 700 m2 g?1 was obtained after TiO2 impregnation. Further, the polyoxometalate, 12‐tungstophosphoric acid (PW12) was dispersed on the surface of TiO2 to form PW12–TiO2–silica hybrid catalytic materials. The catalytic activity of this hybrid material was tested for solvent‐free, aerobic oxidation of n‐hexadecane. The experimental investigation shows that PW12–TiO2 nanocrystals did not block the pore channels and gave good conversion. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献