Photo System

Enkaryodc Phototrophs Possess Two Disdnet Photo.systems... 

Since the compartmentalization occurs as a result of microphase separation of an amphiphilic polyelectrolyte in aqueous solution, an aqueous system is the only possible object of study. This limitation is a disadvantage from a practical point of view. Our recent studies, however, have shown that this disadvantage can be overcome with a molecular composite of an amphiphilic polyelectrolyte with a surfactant molecule [129], This composite was dissolvable in organic solvents and dopable in polymer film, and the microphase structure was found to remain unchaged in the composite. This finding is important, because it has made it possible to extend the study on photo-systems involving the chromophore compartmentalization to organic solutions and polymer solid systems. 

Advanced Photon Source (APS), 26 412 Advanced Photo System (APS), 19 266 Advanced power reactors, 17 594—595 Advanced SclairTech dual-reactor system, 20 197... 

Major PEN film applications include substrates for Advanced Photo System (APS) [2] film, where PEN s higher modulus permits the thinner, curl-free films required. Capacitors capable of higher temperature performance in industrial motor windings also make use of PEN s properties. 

The major features for advanced photo-systems relative to the base film are a small-size thrust cartridge and return inside the cartridge. These features require low core-set curl values and high mechanical strength. The cellulose triacetate (CTA), polycarbonate and PET materials currently used in the photographic industry are not able to satisfy these requirements. Some newly developed film materials, such as modified-PET and syndiotactic polystyrene, were also unable to satisfy such requirements. It is known that annealing films just below the Tg (BTA treatment) could reduce core-set curl tendencies. BTA treatments of... 

Pandey et al. recently developed two useful photo systems for one-electron reductive chemistry and applied them to the activation of aldehyde... 

Among the techniques for recognition mentioned earlier we refer now more specifically to sensing by two-dimensional photo systems. 

Figure 3.19. Crystal structure of photo system II irom(Synechoccus elongatus)(Zouni, et al., 2001). Reproduced with permission.

Nugent, J.H.A. 1996. Oxygenic photosynthesis Electron transfer in Photosystem I and Photo-system II. Eur. J. Biochem. 237 519-531. 

Substituted ureas, amides Photo system 11 electron transport 20... 

Two Photo systems Generate a Proton Gradient and NADPH in Oxygenic Photosynthesis... 

Syntheses of metal complexes with porphyrins and bipyridines as mimetics of natural photo systems 03CCR(245)139. 

To explain the Emerson enhancement effect, Govindjee and Rahinowitch ° obtained evidence from the action spectra of the enhancement effect the presence of two distinct forms of Chl-a in vivo presumably present in two different pigment systems. Soon, new experimental evidence in support of the two-photo-system concept was reported independently by Govindjee etal and by Kautsky eta/. from evidence obtained from fluorescence and by Kok and Hoch Duysens " and Witt based on measurements of absorbance changes. We present here two results based on absorbance changes associated with changes in the redox state of electron carriers in the chloroplast. 

Electron transfer copper proteins usually belong to the blue copper proteins (Type 1) azurin is a simple example. This family of proteins are also called cupredoxins, and they participate in many redox reactions involved in processes fundamental to biology, such as respiration or photosynthesis. The striking electron transfer capabilities of blue copper proteins have been studied extensively. Plastocyanin, with a tetrahedral CUN2S2 core, acts as the electron donor to Photo System I in photosynthesis in higher plants and some algae. 

At the same time that NADPH is being produced, the combination of the photo systems also produces a concentration gradient of protons. Enzymes in the cell use this proton gradient to produce ATP from ADP. Thus, the light cycle produces two high energy molecules NADPH and ATP. 

Plastoquinones QH is a molecule in the electron transfer system betweeen photosystem II (PSII) and photosystem I. The sequence of carriers is as follows Pheophytin -> QA -> QB -> QH -> Cytochrome b6f. Plastoquinone QH2 is the photo synthetic equivalent of coenzyme Q of the electron transport system. It moves freely in the thylakoid membrane, carry electrons between the photo system II complex and the cytochrome b6f complex (Figure 17.12). Electron transfer involving plastoquinones is shown here. Reduction of a plastoquinone creates a plastoquinol. 

Phylloquinone Al (also known as vitamin Kl) is an electron carrier in the system leading from photo system I to NADP... 

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