Bacterial Photosynthetic Pathways Probed by Two-Dimensional Electronic Spectroscopy

有了这个奖项，PI将采用二维电子光谱（2DES）来研究光合紫色细菌的天线和反应中心之间的定向超快能量转移的潜在物理机制。该研究计划将推动2DES作为研究自然光合系统的强大和定量方法的能力，并使用2DES解决有关紫色细菌光合作用的公开问题。具体而言，本研究旨在回答以下问题：1）振动和电子相干在紫色细菌的能量转移和电荷分离中的作用是什么？2)紫色细菌如何重塑它们的能量景观，以调节高光照和低光照条件下的能量转移？本研究旨在扩展2DES光谱的能力，以进行第一个2DES实验的单晶光合复合物，以及第一个2DES实验的整个细胞。2DES的能力的改进，以及它作为模型系统为紫色细菌中能量转移和电荷分离的理论建模提供反馈的能力，最终将为更好地理解更复杂的植物光系统铺平道路。理解相干性在光合能量转移和电荷分离中的作用可能会推动这些过程的新理论模型的发展。该奖项还旨在通过公共教育宣传科学的积极形象，特别是鼓励女性和少数族裔通过外展活动和指导本科生研究进入科学职业。该项目由物理系生命系统物理学项目和分子与细胞生物科学系分子生物物理学项目共同支持。

With this award the PI will employ two-dimensional electronic spectroscopy (2DES) to investigate the underlying physical mechanisms governing the directional ultrafast transfer of energy between the antennae and reaction centers of photosynthetic purple bacteria. The program of research will both push the capabilities of 2DES as a powerful and quantitative method for studying natural photosynthetic systems, and use 2DES to address open questions about photosynthesis in purple bacteria. Specifically, this research aims to answer the following questions: 1) What are the roles of vibrational and electronic coherence in energy transfer and charge separation in purple bacteria? 2) How do purple bacteria remodel their energy-landscape to regulate energy transfer under high and low light conditions? This research aims to extend the capabilities of 2DES spectroscopy to perform the first 2DES experiments on single crystals of photosynthetic complexes as well as the first 2DES experiments on whole cells. Improvements in the capabilities of 2DES, and its ability to provide feedback to theoretical modeling of energy transfer and charge separation in purple bacteria as a model system will ultimately pave the way for a better understanding of the more complex plant photosystems. Understanding the role of coherence in photosynthetic energy transfer and charge separation may drive the development of new theoretical models of these processes. The award also aims to promote a positive image of science through public education, and in particular to encourage women and minorities to enter careers in science through outreach activities and mentored undergraduate research.This project is being jointly supported by the Physics of Living Systems program in the Division of Physics and the Molecular Biophysics Program in the Division of Molecular and Cellular Biosciences.