Charge separation in photosystem II: a comparative and evolutionary overview
Tanai Cardona1, Arezki Sedoud, Nicholas Cox
1Institut de Biologie et Technologies de Saclay, URA 2096 CNRS, CEA Saclay, 91191 Gif-sur-Yvette, France.
Biochimica Et Biophysica Acta
|August 13, 2011
Summary
Comparing photosystem II (PSII) and purple bacterial reaction centres reveals key differences. These distinctions in charge separation and electron acceptors are crucial for PSII
Area of Science:
- Biochemistry
- Photosynthesis Research
- Molecular Biology
Background:
- The purple bacterial reaction centre (BRC) serves as a simplified model for understanding the photosystem II (PSII) reaction centre.
- Comparative studies are essential for elucidating the complex functions of PSII.
Purpose of the Study:
- To provide an overview of similarities between PSII and BRC, focusing on charge separation and electron acceptors.
- To discuss key differences between PSII and BRC, informed by advancements in PSII knowledge.
- To correlate these differences with the functional requirements of water splitting, regulation, and photoprotection in PSII.
Main Methods:
- Comparative analysis of reaction centre structures and functions.
- Review of existing literature on PSII and BRC.
- Functional and evolutionary analysis of PSII.
Main Results:
- Identified similarities in charge separation and electron acceptor mechanisms between PSII and BRC.
- Highlighted significant differences in PSII related to high oxidation potentials for water splitting.
- Uncovered PSII-specific features linked to regulation and protection against photodamage during assembly, repair, and function.
Conclusions:
- Differences between PSII and BRC are critical for PSII's unique role in water splitting and its regulatory mechanisms.
- Understanding these distinctions provides insights into the evolution and protective strategies of the PSII reaction centre.
- This comparative approach enhances our knowledge of PSII's complex biochemistry and function.
Related Concept Videos
01:22Photosystem II
The multi-protein complex photosystem II (PS II) harvests photons and transfers their energy through its bound pigments to its reaction center, and ultimately to photosystem I (PSI) through the electron transport chain. The pigments responsible for caputirng the light energy in photosystems include chlorophyll a, chlorophyll b, and carotenoids.
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
01:27Photosystem I
Although structurally similar to photosystem II (PSII), photosystem I (PSI) is has a different electron supplier and electron acceptor.
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...
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...
01:32Photosystems
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Functioning of Photosystems
Photosystems contain many pigment molecules, such as chlorophylls and carotenoids, arranged in a particular organization across two domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
Functioning of Photosystems
Photosystems contain many pigment molecules, such as chlorophylls and carotenoids, arranged in a particular organization across two domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
01:34The Z-Scheme of Electron Transport in Photosynthesis
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01:29The Photochemical Reaction Center
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01:26Oxygenic Photosynthesis
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