Author :
Publisher :
ISBN 13 : 9789464231007
Total Pages : 0 pages
Book Rating : 4.2/5 (31 download)
Book Synopsis Harvesting Far-red Light by :
Download or read book Harvesting Far-red Light written by and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Oxygenic photosynthesis is the fundamental process by which sunlight energy is stored as chemical energy in organic compounds and oxygen is released in the atmosphere. It starts with the capture of a photon by one of the pigments embedded within one of the two photosystems, Photosystem I (PSI) or II (PSII). These photosystems are large assemblies of many pigments held together by the protein scaffold. The absorption of the photon brings the pigment to an electronic excited state. The excitation energy is then transferred from pigment-to-pigment to the reaction center (RC) of the photosystem, where it is used to perform charge separation (CS). The pigment-to-pigment energy transfer within photosynthetic complexes occurs on a very fast, femtosecond (fs, 10^(-15) second) to picosecond (ps, 10^(-12) second) timescale, which ensures that the photosystems are extremely efficient in using the energy for charge separation. In this thesis, aspects of the light-harvesting of photosynthetic pigment-protein complexes were investigated. The spectroscopic properties (absorption, emission) and energy-transfer processes were studied with a variety of different techniques, including advanced ultrafast time-resolved spectroscopic methods (two-dimensional electronic spectroscopy (2DES) and time-resolved fluorescence spectroscopy). In these time-resolved experiments, the complexes are excited with ultrashort (fs temporal width) pulses of light, after which the optical response (photon-echo, fluorescence) is monitored in time. By measuring these signals, excitation energy transfer (EET) and energy trapping within these complexes can be determined. Oxygenic photosynthesis is mainly powered by visible light in the 400–700 nm range. Expanding the absorption range to 750 nm would result in 19% more photons available for photosynthesis [Chen, M. & Blankenship, R. E. (2011) Trends Plant Sci., 16, 427–431].