Document Detail

Evidence that the variable fluorescence in Chlorella is recombination luminescence.
MedLine Citation:
PMID:  3896315     Owner:  NLM     Status:  MEDLINE    
The fluorescence lifetime of oxygen-forming photosynthetic systems as a function of closed traps has been studied by several groups using light and poisons (usually 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU)) to fix the closed trap state during the experiment. These measurements have now been carried out using light alone, by means of pump and probe laser pulses and a very efficient fast photomultiplier-digitizing system. It is found that the absolute amplitude of fast fluorescence (mean tau, approx. 0.3 ns) remains constant until over half the traps are filled. The amplitude of the slow fluorescence (tau approximately equal to 1.2 ns) increases with pump energy, and its response is best fit with a lag or finite rise-time of approx. 200 ps. This novel result is consistent with the hypothesis that the slow component of the fluorescence is actually recombination luminescence in the trap. Thus, the full trapping time, i.e., the time to form the P+I- state from an excitation in the O2 photosystem, is relatively slow.
D C Mauzerall
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Biochimica et biophysica acta     Volume:  809     ISSN:  0006-3002     ISO Abbreviation:  Biochim. Biophys. Acta     Publication Date:  1985 Aug 
Date Detail:
Created Date:  1985-10-04     Completed Date:  1985-10-04     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0217513     Medline TA:  Biochim Biophys Acta     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  11-6     Citation Subset:  IM    
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MeSH Terms
Chlorella / metabolism,  radiation effects*
Chlorophyll / radiation effects
Chloroplasts / radiation effects
Fluorometry* / instrumentation,  methods
Light-Harvesting Protein Complexes
Luminescent Measurements*
Oxygen / biosynthesis
Photic Stimulation / instrumentation
Photosynthesis / radiation effects*
Photosynthetic Reaction Center Complex Proteins
Plant Proteins / radiation effects
Grant Support
Reg. No./Substance:
0/Light-Harvesting Protein Complexes; 0/Photosynthetic Reaction Center Complex Proteins; 0/Plant Proteins; 1406-65-1/Chlorophyll; 7782-44-7/Oxygen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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