Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Quantum biology: Algae evolved to switch quantum coherence on and off

17.06.2014

A UNSW Australia-led team of researchers has discovered how algae that survive in very low levels of light are able to switch on and off a weird quantum phenomenon that occurs during photosynthesis.

The function in the algae of this quantum effect, known as coherence, remains a mystery, but it is thought it could help them harvest energy from the sun much more efficiently. Working out its role in a living organism could lead to technological advances, such as better organic solar cells and quantum-based electronic devices.


A scanning electron microscope image of cryptophytes. A UNSW Australia-led team has discovered how cryptophytes that survive in very low levels of light are able to switch on and off a weird quantum phenomenon that occurs during photosynthesis.

Credit: CSIRO

The research is published in the journal Proceedings of the National Academy of Sciences.

It is part of an emerging field called quantum biology, in which evidence is growing that quantum phenomena are operating in nature, not just the laboratory, and may even account for how birds can navigate using the earth's magnetic field.

"We studied tiny single-celled algae called cryptophytes that thrive in the bottom of pools of water, or under thick ice, where very little light reaches them," says senior author, Professor Paul Curmi, of the UNSW School of Physics.

"Most cryptophytes have a light-harvesting system where quantum coherence is present. But we have found a class of cryptophytes where it is switched off because of a genetic mutation that alters the shape of a light-harvesting protein.

"This is a very exciting find. It means we will be able to uncover the role of quantum coherence in photosynthesis by comparing organisms with the two different types of proteins."

In the weird world of quantum physics, a system that is coherent – with all quantum waves in step with each other – can exist in many different states simultaneously, an effect known as superposition. This phenomenon is usually only observed under tightly controlled laboratory conditions.

So the team, which includes Professor Gregory Scholes from the University of Toronto in Canada, was surprised to discover in 2010 that the transfer of energy between molecules in the light harvesting systems from two different cryptophyte species was coherent.

The same effect has been found in green sulphur bacteria that also survive in very low light levels.

"The assumption is that this could increase the efficiency of photosynthesis, allowing the algae and bacteria to exist on almost no light," says Professor Curmi.

"Once a light-harvesting protein has captured sunlight, it needs to get that trapped energy to the reaction centre in the cell as quickly as possible, where the energy is converted into chemical energy for the organism.

"It was assumed the energy gets to the reaction centre in a random fashion, like a drunk staggering home. But quantum coherence would allow the energy to test every possible pathway simultaneously before travelling via the quickest route."

In the new study, the team used x-ray crystallography to work out the crystal structure of the light-harvesting complexes from three different species of cryptophytes.

They found that in two species a genetic mutation has led to the insertion of an extra amino acid that changes the structure of the protein complex, disrupting coherence.

"This shows cryptophytes have evolved an elegant but powerful genetic switch to control coherence and change the mechanisms used for light harvesting," says Professor Curmi.

The next step will be to compare the biology of different cryptophytes, such as whether they inhabit different environmental niches, to work out whether the quantum coherence effect is assisting their survival.

###

The team was led by UNSW's Dr Stephen Harrop and Dr Krystyna Wilk and includes researchers from the University of Toronto, the University of Padua, the University of British Columbia, the

University of Cologne and Macquarie University.

Media contacts:

Professor Paul Curmi: + 612 9385 4552, p.curmi@unsw.edu.au

UNSW Science media officer: Deborah Smith, + 612 9385 7307, +61 (0) 478 492 060, deborah.smith@unsw.edu.au

Deborah Smith | Eurek Alert!
Further information:
http://www.unsw.edu.au

More articles from Life Sciences:

nachricht Faster detection of pathogens in the lungs
24.06.2016 | Universität Zürich

nachricht How yeast cells regulate their fat balance
23.06.2016 | Goethe-Universität Frankfurt am Main

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First experimental quantum simulation of particle physics phenomena

Physicists in Innsbruck have realized the first quantum simulation of lattice gauge theories, building a bridge between high-energy theory and atomic physics. In the journal Nature, Rainer Blatt‘s and Peter Zoller’s research teams describe how they simulated the creation of elementary particle pairs out of the vacuum by using a quantum computer.

Elementary particles are the fundamental buildings blocks of matter, and their properties are described by the Standard Model of particle physics. The...

Im Focus: Is There Life On Mars?

Survivalist back from Space - 18 months on the outer skin of the ISS

A year and a half on the outer wall of the International Space Station ISS in altitude of 400 kilometers is a real challenge. Whether a primordial bacterium...

Im Focus: CWRU physicists deploy magnetic vortex to control electron spin

Potential technology for quantum computing, keener sensors

Researchers at Case Western Reserve University have developed a way to swiftly and precisely control electron spins at room temperature.

Im Focus: Physicists measured something new in the radioactive decay of neutrons

The experiment inspired theorists; future ones could reveal new physics

A physics experiment performed at the National Institute of Standards and Technology (NIST) has enhanced scientists' understanding of how free neutrons decay...

Im Focus: Discovery of gold nanocluster 'double' hints at other shape changing particles

New analysis approach brings two unique atomic structures into focus

Chemically the same, graphite and diamonds are as physically distinct as two minerals can be, one opaque and soft, the other translucent and hard. What makes...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ERES 2016: The largest conference in the European real estate industry

09.06.2016 | Event News

Networking 4.0: International Laser Technology Congress AKL’16 Shows New Ways of Cooperations

24.05.2016 | Event News

Challenges of rural labor markets

20.05.2016 | Event News

 
Latest News

Nanoscientists develop the 'ultimate discovery tool'

24.06.2016 | Materials Sciences

Russian physicists create a high-precision 'quantum ruler'

24.06.2016 | Physics and Astronomy

Hubble confirms new dark spot on Neptune

24.06.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>