Related Experiment Video
Updated: May 31, 2026
09:40
Electron Spin Resonance Micro-imaging of Live Species for Oxygen Mapping
Published on: August 26, 2010
Oxygen evolving complex in photosystem II: better than excellent
Mohammad Mahdi Najafpour1, Govindjee
1Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran. mmnajafpour@iasbs.ac.ir
Dalton Transactions (Cambridge, England : 2003)
|July 8, 2011
Summary
The oxygen-evolving complex in photosystem II uses a manganese-calcium cluster to split water, providing insights for artificial photosynthesis catalysts.
Area of Science:
- Biochemistry
- Photosynthesis research
- Bioinorganic chemistry
Background:
- Photosystem II contains a manganese-calcium cluster crucial for water oxidation.
- This natural system splits water using sunlight energy.
- Understanding its structure and mechanism is key for biomimetic applications.
Purpose of the Study:
- To analyze the structure and mechanism of the oxygen-evolving complex.
- To derive strategies for synthesizing efficient water oxidation catalysts.
- To advance artificial photosynthesis.
Main Methods:
- Analysis of recent published data on photosystem II.
- Detailed examination of the oxygen-evolving complex architecture.
- Study of surrounding amino acid interactions.
Main Results:
- Detailed architecture of the oxygen-evolving complex and its amino acid environment is available.
- The manganese-calcium cluster's role in water oxidation is highlighted.
- Insights into the natural water-splitting mechanism are provided.
Conclusions:
- The oxygen-evolving complex serves as a model for water splitting.
- Biomimetic strategies can be learned from this natural catalyst.
- Efficient artificial photosynthesis catalysts are a future goal.
Related Concept Videos
01:26Oxygenic Photosynthesis
Oxygenic photosynthesis is a fundamental process in which light energy is harnessed to drive the oxidation of water, leading to the production of molecular oxygen (O₂), adenosine triphosphate (ATP), and nicotinamide adenine dinucleotide phosphate (NADPH). This process is essential for sustaining aerobic life on Earth and is primarily carried out by cyanobacteria, algae, and plants. The core of oxygenic photosynthesis lies in the thylakoid membranes, where chlorophyll pigments facilitate light...
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...
01:30Anoxygenic Photosynthesis
Anoxygenic photosynthesis is a phototrophic process that captures light energy to drive carbon fixation without producing molecular oxygen. Unlike oxygenic photosynthesis, which utilizes water as an electron donor and releases oxygen, anoxygenic phototrophs use alternative electron donors such as hydrogen sulfide (H₂S), elemental sulfur (S⁰), or thiosulfate (S₂O₃²⁻). This process is carried out by diverse groups of bacteria, including purple bacteria, green sulfur bacteria, heliobacteria, and...
01:32Photosystems
Photosystems are multiprotein complexes that form the functional units of photosynthesis in plants, algae, and cyanobacteria. They are found embedded in the membrane of tiny sac-like structures called thylakoids placed inside the chloroplast.
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
The light reactions of photosynthesis assume a linear flow of electrons from water to NADP+. During this process, light energy drives the splitting of water molecules to produce oxygen. However, oxidation of water molecules is a thermodynamically unfavorable reaction and requires a strong oxidizing agent. This is accomplished by the first product of light reactions: oxidized P680 (or P680+), the most powerful oxidizing agent known in biology. The oxidized P680 that acquires an electron from the...