Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists probe the energy transfer process in photosynthetic proteins

03.08.2011
Researchers have developed a new method to probe the fundamental workings of photosynthesis. The new experimental technique could help scientists better understand the nitty-gritty details of nature's amazingly efficient sunlight-to-fuel conversion system.

Plants and other photosynthetic organisms grow by harvesting the sun's energy and storing it in chemical bonds.

Antenna proteins, which are made up of multiple light-absorbing pigments, capture sunlight over a large surface area and then transfer the energy through a series of molecules to a reaction center where it kick-starts the process of building sugars. Photosynthetic processes take place is spaces so tightly packed with pigment molecules that strange quantum mechanical effects can come into play.

When a pigment molecule absorbs light, one of its electrons is boosted into an "excited" higher energy state. If multiple pigments in a protein absorb light nearly simultaneously, their wave-like excitation states may overlap and become linked to one another, affecting the path of the energy transfer.

Researchers from the University of California, Berkeley, led by Graham Fleming, discovered they could test whether this overlap had occurred. The scientists excited a well-studied photosynthetic antenna protein, called Fenna-Matthews-Olson (FMO), with two different frequencies of laser-light.

When the researchers used a third laser pulse to prompt the protein to release energy, they found it emitted different frequencies than those it had received, a sign that the two excitation states had linked. Alternative methods for observing overlapping excitations had been proposed before, but the new technique may be easier to implement since it relies only on frequency —or color—shifts, and not on precisely timed pulses.

"It is a relatively simple task to separate colors from each other," says team member Jahan Dawlaty, who also noted that the evidence of overlap was not hidden among other optical effects, as it might be when using a different technique. The team's results are published in the American Institute of Physics' Journal of Chemical Physics (JCP). The new method could be used to create a catalogue of the various excitation states in FMO and their potential combinations, the team says.

"The experiment is interesting and was carried out in a novel way," says Shaul Mukamel, a chemist at University of California, Irvine, who was not part of the research team. Mukamel noted that the technique might also be applied to larger complexes and reactions centers. Probing energy levels and pigment couplings in photosynthetic systems is essential to understanding, modeling, and testing the function of these systems, he says.

And, with better understanding, human engineers might one day be able to capitalize on the same energy conversion tactics that photosynthetic organisms have developed over billions of years, notes Ed Castner, editor of JCP and a chemist at Rutgers University in New Jersey.

"The annual total for human energy usage on our planet is roughly equivalent to the amount of light energy incident on the planet in a single hour," says Castner. "To address our needs for safe, sustainable and renewable fuels, it is clearly urgent to understand how photosynthesis works."

Catherine Meyers | EurekAlert!
Further information:
http://www.aip.org

More articles from Life Sciences:

nachricht More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>