Carotenoids energy-transfer

In pure water, electron or energy transfer to carotenoid aggregates is obstructed by the membrane of outside-directed polar groups (Sliwka et al. 2007), Figure 3.14. 

Sliwka HR, Melp TB, Foss BJ, Abdel-Hafez SH, Partali V, Nadolski G, Jackson H, and Lockwood SE. 2007. Electron- and energy-transfer properties of hydrophilic carotenoids. Chemistry—A European Journal 13(16) 4458 1466. 

The analysis of carotenoid identity, conformation, and binding in vivo should allow further progress to be made in understanding of the functions of these pigments in the photosynthetic machinery. One of the obvious steps toward improvement could be the use of continuously tuneable laser systems in order to obtain more detailed resonance Raman excitation profiles (Sashima et al 2000). This technique will be suitable for the investigation of in vivo systems with more complex carotenoid composition. In addition, this method may be applied for the determination of the energy of forbidden Sj or 2 Ag transition. This is an important parameter, since it allows an assessment of the energy transfer relationship between the carotenoids and chlorophylls within the antenna complex. 

Polivka, T., M. Pellnor, E. Melo, T. Pascher, V. Sundstrom, A. Osuka, and K. R. Naqvi. 2007. Polarity-tuned energy transfer efficiency in artificial light-harvesting antennae containing carbonyl carotenoids peridi-nin and fucoxanthin. J. Phys. Chem. C 110 467 -76. 

Wilkinson, F. and Ho, W.-T. 1978. Electronic energy transfer from singlet molecular oxygen to carotenoids. Spectrosc. Lett. 11 455-463. 

The two-pigment-hypothesis explaining the two-peak action spectra (360 and 450 nm) is supported by blue fluorescing spots on the avena coleoptile, if it is excited in the UV162). An energy transfer from this pigment to a carotenoid is suggested. 

Singlet Energy Transfer from Carotenoids to Chlorophylls. .. 168... 

Singlet Energy Transfer from Chlorophylls to Carotenoids. . . 170... 

A, Absorption chi, chlorophyll car, carotenoid EET, excitonic energy transfer EF, exoplasmic fracture face EM, electron microscopy FWHM, full width at half maximum lEF, Isoelectric Focusing, LD, linear dichroism LHC, light harvesting complex PAGE, polyacrylamide gel electophoresis PF, protoplasmic fracture face PS, photosystem RC, reaction centre SDS, sodium dodecyl sulphate SSTT, single step transfer time. 

Walla, P. J., Linden, P. A., Ohta, K., and Eleming, G. R. 2002. Excited-state kinetics of the carotenoid S-1 state in LHC n and two-photon excitation spectra of Intein and beta-carotene in solution Efficient car S-1 -> Chi electronic energy transfer via hot S-1 states J. Phys. Chem. A 106 1909-16. 

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