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 The birth of a new protein
20.10.2017 | University of Arizona

nachricht Building New Moss Factories
20.10.2017 | 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: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>