Primary Processes in Fe-S-Type Photosynthetic Reaction Centers

9418415个布兰肯希普实验是为了扩展目前对光合作用反应中心中能量捕获过程、初级光化学和早期次级电子转移反应的理解，这些反应中心包含FeS中心作为早期电子受体。将要研究的特殊系统包括原始无氧生物的反应中心，即已知的幽门杆菌，以及产氧光合作用生物的光系统I。具体建议的实验包括用低温皮秒瞬时吸收光谱研究幽门螺杆菌和光系统I中的能量转移和捕获，测量两个系统中蓝光区的皮秒瞬时吸光度，以及利用EPR和毫秒时间尺度瞬时吸收光谱研究幽门螺杆菌中的二次电子转移反应。这些实验将对含有完整核心天线颜料的反应中心的能量捕获过程提供新的见解，并将有助于识别和表征这些系统中的一些早期电子受体，包括叶绿素、苯二酚和FeS中心。这个项目将增加我们对植物和其他光合作用生物如何将太阳光能量转化为化学能的理解。光合作用过程提供了我们所有的食物和大部分的能量需求。光合作用如何工作的许多方面在深层次上还没有被理解。这个项目的目的是让人们详细了解这一重要生物过程的化学机制。***

9418415 Blankenship Experiments are proposed to extend the current understanding of the energy trapping processes, primary photochemistry and early secondary electron transfer reactions in photosynthetic reaction centers that contain FeS centers as early electron acceptors. The particular systems that will be studied included reaction centers from the primitive anoxygenic organisms known as heliobacteria as well as Photosystem I of oxygenic photosynthetic organisms. Specific proposed experiments include low-temperature picosecond transient absorbance spectroscopic studies of energy transfer and trapping in both heliobacteria and Photosystem I, picosecond transient absorbance measurement in the blue spectral region in both systems, and investigation of secondary electron transfer reactions in heliobacteria monitored using EPR and millisecond timescale transient absorbance spectroscopy. These experiments will give new insights into the energy trapping process in reaction centers that contain integral core antenna pigments and will help to identify and characterize some of the early electron acceptors in these systems, including chlorophylls, quinones and FeS centers. %%% This project will increase our understanding of how plants and other photosynthetic organisms convert the energy of sunlight into chemical energy. The process of photosynthesis supplies all of our food and most of our energy needs. Many aspects of how photosynthesis works are not understood at a deep level. This project is designed to give detailed knowledge of the chemical mechanism of this essential biological process. ***