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Updated: May 31, 2026
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Evaluation of Photosynthetic Behaviors by Simultaneous Measurements of Leaf Reflectance and Chlorophyll Fluorescence Analyses
Published on: August 9, 2019
Light-induced quinone reduction in photosystem II
Frank Müh1, Carina Glöckner, Julia Hellmich
1Max-Volmer-Laboratorium für Biophysikalische Chemie, Technische Universität Berlin, Strasse des 17. Juni 135, D-10623 Berlin, Germany.
Biochimica Et Biophysica Acta
|June 18, 2011
Summary
Photosystem II
Area of Science:
- Biochemistry
- Photosynthesis research
- Molecular biology
Background:
- Photosystem II (PSII) is the central enzyme complex in oxygenic photosynthesis.
- It catalyzes the light-driven oxidation of water and reduction of plastoquinone.
- PSII is located in the thylakoid membrane of cyanobacteria, algae, and plants.
Purpose of the Study:
- To review current knowledge on the acceptor side of the PSII core complex.
- To focus on quinone binding sites and related components.
- To compare PSII with reaction centers of purple bacteria.
Main Methods:
- Literature review of existing research on Photosystem II.
- Analysis of structural and functional data related to quinone binding.
- Comparative analysis with other photosynthetic reaction centers.
Main Results:
- Detailed description of the primary (QA) and secondary (QB) quinone binding sites.
- Discussion of quinone diffusion channels and the third quinone (QC).
- Exploration of lipid relevance, cytochrome b559 interactions, and QA's role in photoprotection.
Conclusions:
- The acceptor side of PSII is a complex system involving multiple quinones and associated proteins.
- Understanding these components is crucial for comprehending photosynthesis and photoinhibition.
- Further research is needed on enigmatic components like cytochrome b559.
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Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
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