| Photosynthesis is the dominant form of solar energy conversion on the planet, making it critical to understand the fundamentals of the process in order to effectively mimic and improve upon it for human energy needs. The initial stages of photosynthesis include light harvesting and chemical conversion of that harvested energy via electron transport, with both of these stages relying on pigments (or chromophores) such as chlorophyll and specific protein architectures for the processes. In this work, the fundamental underpinnings of photosynthetic light harvesting and electron transport are explored via spectroscopy of various photosynthetic systems with altered natural pigments and proteins. Specifically, these include: 1) chlorophyll-like chromophores containing unnatural functional groups and their altered photophysical properties (such as red-shifted absorption), 2) purple bacterial reaction centers with modified native protein architecture and pigment content with increased 'wrong-way' electron transfer, and 3) purple bacteria wherein the non-photosynthetic pigment-protein complex yellow fluorescent protein (YFP) was added to the bacteria's natural reaction center, resulting in enhanced light-harvesting capacity. |
