能量从植物体转移到光系统I,温度为77K
Ivo H M van Stokkum1, Parveen Akhtar2, Avratanu Biswas1,2,3
1Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, Netherlands.
Frontiers in plant science
|December 11, 2023
概括
生物生物体有效地将能量转移到蓝藻细菌中的光系统I (PSI). 这项研究揭示了特定的相互作用和从 phycobilisomes 到 PSI 的快速能量转移,比内部平衡更快.
科学领域:
- 光合作用研究研究光合作用.
- 蓝藻细菌的能量转移方式
- 生物物理学的生物物理.
背景情况:
- 植物体是光系统I (PSI) 和光系统II (PSII) 在蓝藻细菌中的关键光采集天线.
- 从植物体到PSI的直接能量传递机制尚未完全理解.
研究的目的:
- 研究蓝菌中 phycobilisomes 和 PSI 之间的激发能量传递和捕获动态.
- 为了阐明能量转移的途径和动力学,在体外和体内.
主要方法:
- 像素秒的时间分辨率光光谱在77K.
- 研究了孤立的PSI,植物和一个PSII缺乏突变的Synechocystis sp. 在PCC 6803中.
- 从孤立的复合体和整个细胞的动力学同时进行目标分析.
主要成果:
- 在约800ps的phycobilisome终端发射器之间建立了最慢的平衡时间表.
- 从 phycobilisome 终端发射器到 PSI 的量化能量转移,其速率常数为42 ns-1,用于约40%的 phycobilisomes.
- 观察到的能量转移率到PSI超过内部物理平衡平衡率.
结论:
- 证明了特定的 phycobilisome-PSI 相互作用,促进了快速的能量转移.
- 表明很大一部分植物体直接和有效地将能量转移到PSI.
- 显示剩余的植物体要么没有连接,要么呈现缓慢的能量转移到PSI.
相关概念视频
Photosystem I
62.4K
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...
62.4K
Photosystem II
70.6K
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...
70.6K
Photosystems
4.9K
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...
4.9K
The Photochemical Reaction Center
4.1K
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...
4.1K
The Z-Scheme of Electron Transport in Photosynthesis
10.2K
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...
10.2K
Light as Energy
78.7K
The energy required to carry out photosynthesis is light— typically electromagnetic radiation from the sun. The range of all possible wavelengths is known as the electromagnetic spectrum.
Photons
A photon is a discrete electromagnetic particle or bundle of energy. Photons are characterized by their frequency, wavelength, and amplitude, similar to the properties of a wave. Waves with higher frequencies transmit more energy and have shorter wavelengths than longer wavelengths that transmit...
Photons
A photon is a discrete electromagnetic particle or bundle of energy. Photons are characterized by their frequency, wavelength, and amplitude, similar to the properties of a wave. Waves with higher frequencies transmit more energy and have shorter wavelengths than longer wavelengths that transmit...
78.7K


