Navigation Links
ASU researchers synthesize molecule with self-control
Date:5/12/2008

TEMPE, Ariz. Plants have an ambivalent relationship with light. They need it to live, but too much light leads to the increased production of high-energy chemical intermediates that can injure or kill the plant.

The intermediates do this because the efficient conversion of sunlight into chemical energy cannot keep up with sunlight streaming into the plant.

The intermediates dont have anywhere to go because the system is jammed up down the line, says ASU chemist Devens Gust. Plants employ a sophisticated process to defend against damage.

To better understand this process, Gust, along with fellow ASU researchers Thomas Moore and Ana Moore, both professors of chemistry and biochemistry, designed a molecule that mimics what happens in nature. They report results with their molecule in the advanced online publication of Nature Nanotechnology (May 4, 2008).

In nature, plants defend against this sunlight overload process using non-photochemical quenching (NPQ). This process drains off the excess light excitation energy as heat so that it cannot generate the destructive high-energy species.

The ASU-designed molecule works in a similar fashion in that it converts absorbed light to electrochemical energy but reduces the efficiency of the conversion as light intensity increases. The ASU-designed molecule has several components including two light gathering antennas a porphyrin electron donor, a fullerene acceptor and a control unit that reversibly photoisomerizes between a dihydroindolizine (DHI) and a betaine (BT).

When white light (sunlight) shines on a solution of the molecules, light absorbed by the porphyrin (or by the antennas) is converted to electrochemical potential energy. When the white light intensity is increased, the DHI on some molecules change to a different molecular structure, BT, that drains light excitation energy out of the porphyrin and converts it to heat, avoiding the generation of excess electrochemical potential. As the light becomes brighter, more molecules switch to the non-functional form, so that the conversion of light to chemical energy becomes less efficient. The molecule adapts to its environment, regulating its behavior in response to the light intensity.

One hallmark of living cells is their ability to sense and respond to surrounding conditions, explains Thomas Moore. In the case of metabolic control this process involves molecular-level recognition events that are translated into control of a chemical process.

Functionally, this mimics one of the processes in photosynthesis that severely limits the energy conversion efficiency of higher plants, he added. One way in which this work is important is that by understanding these events at the molecular level one can imagine redesigning photosynthesis to improve energy conversion efficiency and thereby come closer to meeting our energy needs.

The research is also important to one aspect of the exploding field of nanotechnology, that of regulation, Gust adds. Biological systems are known for their ability to engage in adaptive self-regulation. The nanoscale components respond to other nanoscale systems and to external stimuli in order to keep everything in balance and functioning properly. The ASU research shows how a bio-regulation system has been captured in a non-biological molecular scale analog process.

Achieving such behavior in human-made devices is vital if we are to realize the promise of nanotechnology, adds Gust. Although the mechanism of control used in the ASU molecule is different from that employed in NPQ, the overall effect is the same as occurs in the natural photosynthetic process.


'/>"/>

Contact: Skip Derra
skip.derra@asu.edu
480-965-4823
Arizona State University
Source:Eurekalert

Related biology news :

1. Researchers identify proteins involved in new neurodegenerative syndrome
2. Texas researchers and educators head for Antarctica
3. MGH researchers describe new way to identify, evolve novel enzymes
4. University of Pennsylvania researchers develop formula to gauge risk of disease clusters
5. U of MN researchers discover noninvasive diagnostic tool for brain diseases
6. U of Minnesota researchers discover noninvasive diagnostic tool for brain diseases
7. Researchers discover new strategies for antibiotic resistance
8. Researchers find new taste in fruit flies: carbonated water
9. Binghamton University researchers investigate evolving malaria resistance
10. UIC researchers find promising new targets for antibiotics
11. Researchers develop simple method to create natural drug products
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/18/2016)... --> --> Competitive Landscape Analysis ... Physical infrastructure and Perimeter Surveillance & Detection Systems ... and the continuing migration crisis in the Middle ... led visiongain to publish this unique report, which is crucial ... & security companies in the border security market and the ...
(Date:3/15/2016)... ALBANY, New York , March 15, 2016 ... a new market report published by Transparency Market Research "Digital ... Growth, Trends and Forecast 2015 - 2023," the global digital ... at US$ 731.9 Mn in 2014 and is forecast to ... to 2023. Growth of micro, small and medium enterprises (MSMEs) ...
(Date:3/14/2016)... 14, 2016 NXTD ) ("NXT-ID" or ... market, announces the airing of a new series of commercials ... of March 21 st .  The commercials will air on ... Squawk on the Street show. --> NXTD ) ... mobile commerce market, announces the airing of a new series ...
Breaking Biology News(10 mins):
(Date:5/19/2016)... MADRID , May 19, 2016 ... di una sessione orale durante il 52 ° ... (abstract n. 8006)    - Le conclusioni ... quanto riguarda i pazienti trattati, di cui il 90% presenta ... di sei mesi o più. Il settantadue per cento dei ...
(Date:5/18/2016)... Fort Washington, PA (PRWEB) , ... May 18, ... ... and at least 1,200 hospitalizations are a direct result of asthma complications.* Costing ... health challenge across the country. , “For too many, the ...
(Date:5/17/2016)... Riyadh, Saudi Arabia (PRWEB) , ... May 17, ... ... for the biopharmaceutical industry, and BioSmartSA, a healthcare consultancy based in Saudi Arabia, ... management of diagnostic services to healthcare providers in the Kingdom of Saudi Arabia ...
(Date:5/17/2016)... ... May 17, 2016 , ... Yukon Medical, a leading ... (Becton, Dickinson and Company) to receive its Global Product Innovation Supplier of the ... made significant contributions to advancing or supporting key BD initiatives, products, processes, and ...
Breaking Biology Technology: