Experimental work on the control of photosystem II in the photosynthetic apparatus of higher plants, mosses and lichens is reviewed on a background of current literature. Transmembrane proton transport during photoassimilatory and photorespiratory electron flows is considered insufficient for producing the intrathylakoid acidification necessary for control of photosystem II activity under exces...

We present a systematic study of the effect of antenna size on energy transfer and trapping in photosystem II. Time-resolved fluorescence experiments have been used to probe a range of particles isolated from both higher plants and the cyanobacterium Synechocystis 6803. The isolated reaction center dynamics are represented by a quasi-phenomenological model that fits the extensive time-resolved ...

Dark-grown Chlamydomonas reinhardtii cultures that were illuminated at low fluence rates before exposure to high-light conditions exhibited a faster rate of recovery from photoinhibition than did dark-grown cells that were directly exposed to photoinhibitory conditions. This pretreatment has been shown to induce the expression of several nuclear heat shock protein 70 (HSP70) genes, including HS...

Photosyntlhesis is presently conceived as a cooperation between 2 photoacts, photosystem I generating a strong reductant and a weak oxidant, photosystem II generating a srong oxidant (yielding O2) and a weak reductant. Coupling between the 2 photosteps presumably occurs between the weak reductant and the weak oxidant, a step possibly generating high energy phosphate. A number of means are avail...

The oxygen-evolving photosystem II particles prepared from spinach chloroplasts with brief sonication and Triton X-100 treatment were subjected to butanol/water phase partitioning. Three peripheral proteins of photosystem II having relative molecular masses of 33,000, 24,000, and 18,000 daltons and a part of the manganese atoms associated with photosystem II were partitioned into the aqueous ph...

In isolated barley chloroplasts, the presence of 2 millimolar ZnSO(4) inhibits the electron transport activity of photosystem II, as measured by photoreduction of dichlorophenolindophenol, O(2) evolution, and chlorophyll a fluorescence. The inhibition of photosystem II activity can be restored by the addition of the electron donor hydroxylamine or diphenylcarbazide, but not by benzidine and MnC...

Histone inhibits the photosystem 1 activities of isolated chloroplasts. This inhibition can be prevented by prior exposure of the chloroplasts to moderate concentrations of inorganic salts. However, even very high concentrations of inorganic salts will not reverse the inhibition, nor is the inhibition reversed by washing the chloroplasts. Exogenous plastocyanin causes a partial reversal of hist...

Photosystem I (PSI), a photoactive protein complex that participates in the light reactions of natural photosynthesis, can exhibit photocatalytic capabilities when incorporated to electrochemical systems. Here we present a simulation for the photoelectrochemical behavior of an electrode modified with a monolayer of Photosystem I complexes during photochronoamperometric experiments in which the ...

Light dependence and kinetics of reversible phosphorylation of the D1 reaction center protein of Photosystem II was studied in pumpkin leaves. At growth light, maximal phosphorylation of D1 was observed after illumination of 1 h, with higher phosphorylation rates at stronger irradiances. 70-85% of D1 became phosphorylated, corresponding to the proportion of the protein in appressed thylakoid me...

Abstract This study intends to propose a novel approach based on fuzzy synthetic evaluation in order to realize power enterprise supply chain performance evaluation. Through the characteristic analysis of power enterprise supply chain, a 2-dimensions mesh framework for power enterprise supply chain performance evaluation is put forward, and the indexes of power enterprise supply chain performan...