Bioenergetic Pathways in the Chloroplast: Photosynthetic Electron Transfer

摘要: In this review, we address bioenergetic pathways in the chloroplast of Chlamydomonas reinhardtii, with a focus on photosynthetic electron transfer. The conversion solar energy into chemical by oxygenic photosynthesis, as performed plants, green algae and cyanobacteria, supports life planet. production oxygen (O2) assimilation carbon dioxide (CO2) organic matter determine, to large extent, composition our atmosphere. Plant photosynthesis is conducted series reactions that occur mainly chloroplast, resulting light-dependent H2O oxidation, NADP+ reduction ATP formation. NADPH ATP, produced linear flow (LEF), are required for fixation via Calvin-Benson-Bassham (CBB) cycle. Besides, transfer may operate cyclic (CEF) mode satisfy cellular demand. Electrons derived from LEF also be diverted various other metabolic pathways, e.g. ferredoxin (FDX). addition, evolved maximize its outcome while minimizing photooxidative stress. regard, mechanisms such non-photochemical quenching (NPQ) state transitions regulate influx at different light availabilities, which feedback proton-motive force (pmf) redox plastoquinone/plastoquinol (PQ) pool, thereby regulating CEF. To overcome possible limitations acceptor side photosystem (PSI), alternative evolved, including flavodiiron proteins (FDPs), allowing safe utilization O2 acceptor, well hydrogenase, utilizes two electrons protons produce H2. Nevertheless, reactive species (ROS) formed, Mehler reaction PSI, why utilized detoxification prevent excessive damage. conclusion, interwoven regulatory network aimed adjusting way not harmful cell.