求达人 翻译下英文文献 关于 光系统Ⅱ和除草剂 通顺Z重要

PhotosystemIIisthemulti-enzymaticchlorophyll-proteincomplex(water-plastoquinoneoxido-reductase)locatedinthethylakoidmembraneofalgae，cyanobacteriaandhigherplants.Itisanint... Photosystem II is the multi-enzymatic chlorophyll-protein complex (water-plastoquinone oxido-reductase) located in the thylakoid membrane of algae， cyanobacteria and higher plants. It is an integral part of the electron transport chain that catalyses primary charge separation. This protein complex consists of over 25 polypeptides， which make up a light-harvesting chlorophyll protein complex (LHCII)， a reaction centre and the water-splitting system， also called the oxygen evolving complex (OEC). The PSII complex also contains the target site of the most widely used photosynthetic herbicides."^ The preparation of a biosensor for the detection of polluting compounds is based on the specific characteristics of PSII. Under illumination PSII drives electron transfer which is inhibited by specific chemical compounds (e.g.， herbicides). Thus， the photosynthetic membrane isolated firom higher plants and photosynthetic micro-organisms， immobilised and stabilised， will serve as the biosensor biomediator. The effect of compounds that alter or inhibit photosynthetic activity， measured as oxygen evolution， electron transport or fluorescence can then be translated and monitored by amperometric or optical systems. Recent experiments that were performed by our this team resulted in amperometric， potentiometric， optical biosensors for herbicides based on isolated and immobilised PSII particles exhibiting stable biological material and a highly sensitive monitoring response (limit of detection in the nanomolar range and for diuron herbicide in the picomolar range).^'^ However， the system is specific to photosynthetic herbicides but not very selective since several classes of compounds (herbicides represented by triazines， ureas， diazines， phenols) can bind to proteins of the PSII complex， most of them to the Dl protein of the reaction centre.