Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Snapshot reveals details about photosynthesis

09.11.2012
Together with a large international research team, Johannes Messinger of Umeå University in Sweden has taken another step toward an understanding of photosynthesis and developing artificial photosynthesis.

With a combination of a x-ray free-electron laser and spectroscopy, the team has managed to see the electronic structure of a manganese complex, a chemical compound related to how photosynthesis splits water.


Caption: Ultra-short x-ray pulse striking molecules containing manganese. Illustration: Greg Stewart, National Accelerator Laboratory vid Stanford University

The experiments used the Linac Coherent Light Source (LCLS), which is a free-electron x-ray laser facility at Stanford University in the US. The wavelength of the laser is roughly the same as the breadth of an atom, and each pulse of light lasts 50 femtoseconds (10-15). This is an extremely short interval of time: there are more femtoseconds in one second than there are seconds in a person’s life. Such extremely short wavelengths and short light pulses constitute ideal conditions for imaging chemical reactions with atomic resolution at room temperature while the chemical reactions are ongoing.

The research group has previously used LCLS to perform structural analyses of isolated photosynthesis complexes from plants’ photosystem II at room temperature. Now the group has combined the method with spectroscopy and is the first team to succeed in seeing at LCLS the electronic structure of a manganese complex similar to that found in photosystem II. Manganese is a transitional metal that, together with calcium and oxygen, forms the water-splitting catalyst in photosystem II.

A very simple example of a spectrometer is a prism, which separates sunlight into all the colors of the rainbow. The spectrometer used in this study functions in a similar manner, but with a group of 16 specialized crystals that diffract the x-rays emitted from the sample in resonse of being excited by an x-ray pulse onto a detector array.

To the delight of the scientists, the manganese compounds remained intact long enough for them to observe detailed information about the electronic structure before the compounds were destroyed by the very intense X-ray laser beam.

“Having both structural information and spectroscopic information means that we can much better understand how the structural changes of the whole complex and the chemical changes on the active surface of the catalysts work together to enable the enzymes to perform complex chemical reactions at room temperature,” says Johannes Messinger, professor at the Department of Chemistry at Umeå University.

The chemical reaction the research group aims to understand is the splitting of water in photosystem II, as this understanding is also key for developing artificial photosynthesis– that is, for building devices for producing hydrogen from sunlight and water. To be able to exploit sunlight for producing fuels that can be stored and the used when needed would help solve the world’s ever-more acute energy problems.

The new research findings are being published in the highly regarded journal Proceedings of the National Academy of Sciences, PNAS.

Two major research projects at Umeå University are focusing on the development of artificial photosynthesis by imitating plants’ very successful way of exploiting solar energy. Both projects (“solar fuels” and “artificial leaf”) are directed by Johannes Messinger, professor at the Department of Chemistry at Umeå University.

Original publication:
Alonso-Mori Roberto, et. al: Energy-dispersive X-ray emission spectroscopy using an X-ray free-electron laser in a shot-by-shot mode. PNAS, November 5 2012, doi:10.1073/pnas.1211384109
For more information, please contact:
Johannes Messinger
Telephone: phone: +46 (0)90-786 59 33
E-mail: johannes.messinger@chem.umu.se

Ingrid Söderbergh | idw
Further information:
http://www.vr.se

More articles from Life Sciences:

nachricht Why do animals fight members of other species?
24.04.2015 | University of California - Los Angeles

nachricht Is a small artificially composed virus fragment the key to a Chikungunya vaccine?
24.04.2015 | Paul-Ehrlich-Institut - Bundesinstitut für Impfstoffe und biomedizinische Arzneimittel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Elektromobilität: Ultraleichtes Kraftpaket für das elektrische Fliegen

Siemens hat einen einzigartigen Elektromotor entwickelt, der hohe Leistung mit einem minimalen Gewicht kombiniert. Durch konsequente Optimierung aller Komponenten stellt der neue Antrieb in seiner Klasse einen Weltrekord beim Leistungsgewicht auf. Dadurch kommt der routinemäßige Einsatz von elektrisch angetriebenen Flugzeugen oder Helikoptern einen großen Schritt näher.

Manchmal lässt sich eine technische Revolution ganz knapp in einer einzigen Zahl zusammenfassen. In diesem Fall lautet sie: fünf Kilowatt pro Kilogramm – das...

Im Focus: Fast and Accurate 3-D Imaging Technique to Track Optically-Trapped Particles

KAIST researchers published an article on the development of a novel technique to precisely track the 3-D positions of optically-trapped particles having complicated geometry in high speed in the April 2015 issue of Optica.

Daejeon, Republic of Korea, April 23, 2015--Optical tweezers have been used as an invaluable tool for exerting micro-scale force on microscopic particles and...

Im Focus: Von Innen nach Außen: Rätsel der galaktischen Scheiben gelöst

Ein Team von Astronomen unter der Leitung von Ivan Minchev, Wissenschaftler am Leibniz-Institut für Astrophysik Potsdam (AIP), hat mithilfe hochmoderner theoretischer Modelle das Rätsel um die Entwicklung der Galaxienscheiben gelöst. Die jetzt veröffentlichte Studie zeigt, dass sich Sternpopulationen gleichen Alters durch Galaxienkollisionen nach außen hin ausweiten. Ähnlich wie die Blüten einer Rose reichern sich diese Populationen schichtweise in der Galaxie an und formen so allmählich die dicke Scheibe.

„Wir können nun zum ersten Mal zeigen, dass dicke Scheiben nicht nur aus alten Sterngenerationen bestehen, sondern – in einem größeren Abstand zum...

Im Focus: NOAA, Tulane identify second possible specimen of 'pocket shark' ever found

Pocket sharks are among the world's rarest finds

A very small and rare species of shark is swimming its way through scientific literature. But don't worry, the chances of this inches-long vertebrate biting...

Im Focus: Morbus Crohn: neuer Entstehungsmechanismus entschlüsselt

Bakteriengemeinschaften verursachen Darmentzündung

Morbus Crohn zählt zu den chronisch-entzündlichen Darmerkrankungen (CED). Bei der Krankheit spielt die genetische Veranlagung eine Rolle - und offenbar auch...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

Internationale Familienunternehmensforschung

24.04.2015 | Veranstaltungen

Internationaler Tag der Immunologie am 29. April 2015

24.04.2015 | Veranstaltungen

Wirtschaftsempfang 2015: WissensRÄUME

24.04.2015 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Simulation und virtuelle Welten: Virtueller Messerundgang mit dem Smartphone

24.04.2015 | Informationstechnologie

Elektromobilität: Ultraleichtes Kraftpaket für das elektrische Fliegen

24.04.2015 | Energie und Elektrotechnik

Siemens integriert Sitop-Stromversorgung in Prozessleitsystem Simatic PCS 7

24.04.2015 | Messenachrichten