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 Tag it EASI – a new method for accurate protein analysis
19.06.2018 | Max-Planck-Institut für Biochemie

nachricht How to track and trace a protein: Nanosensors monitor intracellular deliveries
19.06.2018 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Carbon nanotube optics provide optical-based quantum cryptography and quantum computing

19.06.2018 | Physics and Astronomy

How to track and trace a protein: Nanosensors monitor intracellular deliveries

19.06.2018 | Life Sciences

New material for splitting water

19.06.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>