Calculation of connectivity of photosynthetic units in intact cells of rhodobacter sphaeroides

P. Maróti, Emese Asztalos

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

The kinetics of the bacteriochlorophyll fluorescence of intact cells of photosynthetic bacterium Rhodobacter sphaeroides was measured under rectangular shape of intense excitation in the microsecond time range. The interest was focused to the initial (sigmoidal) rise of the fluorescence to characterize the connectivity of the photosynthetic units. As the rate of the primary photochemistry (charge separation) was set to be much larger than that of the re-reduction of the oxidized dimer of the reaction center, there was reciprocity between light intensity and photochemical rise time, and therefore a simple model of single fluorescence (photochemical) quencher could be applied. By linearization of the fluorescence induction kinetics, the connectivity parameter p could be directly obtained (p = 0.47 ± 0.01) and was independent on the intensity of the light excitation. The mean value of the number of steps (visits) in the antenna was calculated before an exciton is either trapped by an open reaction center (it is utilized by photochemistry) or dissipated in form of fluorescence emission. According to these calculations, the mean number of steps is less than 1 if p < 0.5, even if all of the reaction centers are closed. The observed small p value includes highly restricted mobility of excitions among the photosynthetic units.

Original languageEnglish
Title of host publicationAdvanced Topics in Science and Technology in China
PublisherSpringer
Pages27-31
Number of pages5
DOIs
Publication statusPublished - Jan 1 2013

Publication series

NameAdvanced Topics in Science and Technology in China
ISSN (Print)1995-6819
ISSN (Electronic)1995-6827

Fingerprint

Fluorescence
Photochemical reactions
Bacteriochlorophylls
Kinetics
Linearization
Excitons
Dimers
Bacteria
Antennas

Keywords

  • Bacterial photosynthesis
  • Coupling of PSUs
  • Exciton migration
  • Fluorescence induction
  • Sigmoidal rise

ASJC Scopus subject areas

  • Engineering(all)
  • Chemical Engineering(all)
  • General

Cite this

Maróti, P., & Asztalos, E. (2013). Calculation of connectivity of photosynthetic units in intact cells of rhodobacter sphaeroides. In Advanced Topics in Science and Technology in China (pp. 27-31). (Advanced Topics in Science and Technology in China). Springer. https://doi.org/10.1007/978-3-642-32034-7_6

Calculation of connectivity of photosynthetic units in intact cells of rhodobacter sphaeroides. / Maróti, P.; Asztalos, Emese.

Advanced Topics in Science and Technology in China. Springer, 2013. p. 27-31 (Advanced Topics in Science and Technology in China).

Research output: Chapter in Book/Report/Conference proceedingChapter

Maróti, P & Asztalos, E 2013, Calculation of connectivity of photosynthetic units in intact cells of rhodobacter sphaeroides. in Advanced Topics in Science and Technology in China. Advanced Topics in Science and Technology in China, Springer, pp. 27-31. https://doi.org/10.1007/978-3-642-32034-7_6
Maróti P, Asztalos E. Calculation of connectivity of photosynthetic units in intact cells of rhodobacter sphaeroides. In Advanced Topics in Science and Technology in China. Springer. 2013. p. 27-31. (Advanced Topics in Science and Technology in China). https://doi.org/10.1007/978-3-642-32034-7_6
Maróti, P. ; Asztalos, Emese. / Calculation of connectivity of photosynthetic units in intact cells of rhodobacter sphaeroides. Advanced Topics in Science and Technology in China. Springer, 2013. pp. 27-31 (Advanced Topics in Science and Technology in China).
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