Related Experiment Video
Updated: May 4, 2026
07:10
Purification of Active Photosystem I-Light Harvesting Complex I from Plant Tissues
Published on: February 3, 2023
1.5K
Current perceptions of Photosystem II
1Department of Biochemistry and Biophysics, Chalmers University of Technology, S-412 96, Göteborg, Sweden.
Photosynthesis Research
|January 15, 2014
Summary
Recent advances have clarified Photosystem II (PSII) organization, identifying D1 and D2 proteins and electron transfer components. However, manganese ion location and water-oxidation mechanisms in PSII remain key research questions.
Area of Science:
- Biochemistry
- Photosynthesis research
- Molecular biology
Background:
- Significant progress in understanding Photosystem II (PSII) structure and function.
- Comparative analysis with purple photosynthetic bacteria has refined PSII organization models.
Purpose of the Study:
- To provide an update on recent advancements in Photosystem II research.
- To highlight key findings in protein components, electron transfer, and membrane organization.
Main Methods:
- Biochemical isolation and characterization of PSII protein components.
- Comparative analysis of photosynthetic bacteria.
- Electron Paramagnetic Resonance (EPR) spectroscopy for signal assignment.
Main Results:
- D1 and D2 intrinsic proteins identified as binding primary reactants and reducing-side components.
- Electron transfer components, including tyrosine radicals and Q400, have been further characterized.
- Primary charge separation in PSII occurs within approximately 3 picoseconds.
Conclusions:
- While PSII organization and electron transfer are better understood, the manganese ion location and water-oxidation mechanism require further investigation.
- Research is ongoing into the organization of PSII within the thylakoid membrane and the roles of lipids and cofactors.
More Related Videos
08:40Separation of Spinach Thylakoid Protein Complexes by Native Green Gel Electrophoresis and Band Characterization using Time-Correlated Single Photon Counting
Published on: February 14, 2019
7.2K
10:20Evaluation of Photosynthetic Behaviors by Simultaneous Measurements of Leaf Reflectance and Chlorophyll Fluorescence Analyses
Published on: August 9, 2019
12.4K
Related Concept Videos
01:22Photosystem II
59.9K
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...
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment...
59.9K
01:27Photosystem I
52.8K
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...
52.8K
01:32Photosystems
7.0K
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...
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...
7.0K
01:29The Photochemical Reaction Center
4.4K
Reaction centers are pigment-protein complexes that initiate energy conversion from photons to chemical entities. Therefore, photochemical reaction center is a more appropriate term that describes these complexes. The Nobel laureates Robert Emerson and William Arnold provided the first experimental evidence of photochemical reaction centers by demonstrating the participation of nearly 2,500 chlorophyll molecules for the release of just one molecule of oxygen. Despite thousands of photosynthetic...
4.4K
01:26Oxygenic Photosynthesis
994
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...
994
01:34The Z-Scheme of Electron Transport in Photosynthesis
12.6K
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...
12.6K