Geacintov NE, Breton J, Swenberg C, Campillo AJ, Hyer RC, Shapiro SL. Picosecond and microsecond pulse laser studies of exciton quenching and exciton distribution in spinach chloroplasts at low temperatures.
BIOCHIMICA ET BIOPHYSICA ACTA 1977;
461:306-12. [PMID:
889822 DOI:
10.1016/0005-2728(77)90180-3]
[Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Studies of the fluorescence quantum yield and decay times, determined at the emission maxima of 685 and 735 nm, using picosecond laser pulses for excitation, indicate that the pigments which are responsible for the 735 nm emission derive their energy by transfer of singlet excitons from the light-harvesting pigments and not by direct absorption of photons. Microsecond pulse laser studies of the fluorescence quantum yields at these two fluorescence wavelengths indicate that long lived quenchers (most probably triplet states), which quench singlet excitions, accumulate preferentially within the long wavelength pigment system which gives rise to the 735 nm emission band.
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