Journal ArticleDOI
Long-wavelength absorbing antenna pigments and heterogeneous absorption bands concentrate excitons and increase absorption cross section
TLDR
It is shown that the kinetics of the energy transfer from a long-wavelength antenna pigment to a hypsochromically absorbing primary donor does not represent a major kinetic limitation and means an evolutionary advantage based on the chromatic adaptation of photosynthetic organelles to spectrally filtered light caused by self-absorption.Abstract:
The light-harvesting apparatus of photosynthetic organisms is highly optimized with respect to efficient collection of excitation energy from photons of different wavelengths and with respect to a high quantum yield of the primary photochemistry. In many cases the primary donor is not an energetic trap as it absorbs hypsochromically compared to the most red-shifted antenna pigment present (long-wavelength antenna). The possible reasons for this as well as for the spectral heterogeneity which is generally found in antenna systems is examined on a theoretical basis using the approach of thermal equilibration of the excitation energy. The calculations show that long-wavelength antenna pigments and heterogeneous absorption bands lead to a concentration of excitons and an increased effective absorption cross section. The theoretically predicted trapping times agree remarkably well with experimental data from several organisms. It is shown that the kinetics of the energy transfer from a long-wavelength antenna pigment to a hypsochromically absorbing primary donor does not represent a major kinetic limitation. The development of long-wavelength antenna and spectrally heterogeneous absorption bands means an evolutionary advantage based on the chromatic adaptation of photosynthetic organelles to spectrally filtered light caused by self-absorption.read more
Citations
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Journal ArticleDOI
Energy Conversion in Natural and Artificial Photosynthesis
TL;DR: This review describes the three key components of solar energy conversion in photosynthesis: light harvesting, charge separation, and catalysis, and these processes are compared in natural and in artificial systems.
Journal ArticleDOI
Energy transfer and trapping in photosystem I.
B. Gobets,R. van Grondelle +1 more
TL;DR: A direct comparison of the energy transfer and trapping properties of the PS I core complexes of cyanobacteria bear a large resemblance to the core complex of plants, and this results in a transmembrane electrochemical gradient that can be used to produce ATP.
Journal ArticleDOI
Spectral Signatures of Photosynthesis. I. Review of Earth Organisms
TL;DR: The "near-infrared (NIR) end" of the red edge to trend from blue-shifted to reddest for snow algae, temperate algae, lichens, mosses, aquatic plants, and finally terrestrial vascular plants is found.
Journal ArticleDOI
Light-harvesting in photosystem I
TL;DR: The light-harvesting properties of the PSI-LHCI complex in relation to protein and pigment organization/composition are described, and the important parameters that assure its very high quantum efficiency are discussed.
Journal ArticleDOI
P700: the primary electron donor of photosystem I.
Andrew N. Webber,Wolfgang Lubitz +1 more
TL;DR: EPR studies of P700(+*) in frozen solution and single crystals indicate a large asymmetry in the electron spin and charge distribution towards one Chl of the dimer, suggesting that the unpaired electron would predominantly reside on the Chl a.
References
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Determination of accurate extinction coefficients and simultaneous equations for assaying chlorophylls a and b extracted with four different solvents: verification of the concentration of chlorophyll standards by atomic absorption spectroscopy
TL;DR: In this paper, the extinction coefficients for chlorophylls a and b in diethylether (Smith, J.H. and Benitez, A.V., eds.), used in this paper as primary standards, were verified by magnesium determination using atomic absorbance spectrophotometry.
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Kinetic and Energetic Model for the Primary Processes in Photosystem II.
TL;DR: The long-lived (nanoseconds) fluorescence generally observed with closed PS II reaction centers is prompt fluorescence and that the amount of primary radical pair formation is decreased significantly upon closing of the RC.
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Excitation energy transfer, trapping and annihilation in photosynthetic systems
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Spectroscopic analysis of bacteriochlorophylls in vitro and in vivo
TL;DR: In this paper, an analysis of extinction cofficients and band areas of these pigments indicates that they are both specialized fornis of BChl, in a molecular ratio of 2P800:1P870.
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Structure and X-ray amino acid sequence of a bacteriochlorophyll a protein from Prosthecochloris aestuarii refined at 1.9 Å resolution
TL;DR: The structure of the water-soluble bacteriochlorophyll a protein (Bchl protein) from the green photosynthetic bacterium Prosthecochloris aestuarii has been refined and has led to an "X-ray sequence".