Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. Earth Science News .




FLORA AND FAUNA
Unlocking Some Key Secrets of Photosynthesis
by Staff Writers
Troy NY (SPX) Jul 04, 2012


The new research focuses on the first of two photochemical reactions that plants use to convert solar energy into chemical energy that takes place within photosystem II. Specifically, the researchers studied the binding and activation of the substrate water molecules in the catalytic site of photosystem II.

New research led by chemists in the Baruch '60 Center for Biochemical Solar Energy Research at Rensselaer Polytechnic Institute is seeking to detail the individual steps of highly efficient reactions that convert sunlight into chemical energy within plants and bacteria.

In a paper published in the recent edition of the Royal Society of Chemistry journal, Energy and Environmental Science, the scientists - led by K. V. Lakshmi, Rensselaer assistant professor of chemistry and chemical biology and scientific lead at the Baruch '60 Center - have provided important information on a specific portion of the photosynthetic process called photosystem II.

It has been a major challenge to directly observe the individual steps of the solar water-splitting reaction that takes place in photosystem II, Lakshmi said. This finding provides new foundational research into how plants efficiently convert energy from the sun and could help inform the development of a new, highly robust, and more efficient generation of solar-energy technologies.

Lakshmi was joined in the research by Rensselaer students Sergey Milikisyants, Ruchira Chatterjee, and Christopher Coates, as well as Faisal H.M. Koua and Professor Jian-Ren Shen of Okayama University in Japan. The research is funded by the Office of Basic Energy Sciences, U.S. Department of Energy.

"The photosynthetic system of plants is nature's most elaborate nanoscale biological machine," said Lakshmi. "It converts light energy at unrivaled efficiency of more than 95 percent compared to 10 to 15 percent in the current man-made solar technologies. In order to capture that efficiency in solar energy technology, we must first tackle the basic science of photosynthesis by understanding the chemistry behind its ultra-efficient energy conversion process in nature."

The new research focuses on the first of two photochemical reactions that plants use to convert solar energy into chemical energy that takes place within photosystem II. Specifically, the researchers studied the binding and activation of the substrate water molecules in the catalytic site of photosystem II.

Photosystem II is a protein complex in plants and cyanobacteria that uses photons of light to split water molecules. This is known as the solar oxidation of water. The protons and electrons resulting from this split are then used by the plant to fuel the remaining systems in the photosynthetic process that transforms light into chemical energy.

"Photosystem II is the engine of life," Lakshmi said. "It performs one of the most energetically demanding reactions known to mankind, splitting water, with remarkable ease and efficiency."

One of the difficulties in studying photosystem II is that conventional methods have not yet been able to deeply probe the photosystem II complex, according to Lakshmi, and the mechanism of the photochemical reactions must be fully understood before bio-inspired technologies that mimic the natural processes of photosynthesis can effectively be developed.

In the new research, the scientists investigated the catalytic site of photosystem II, referred to as the oxygen-evolving complex. This is part of the system that breaks down the water. It does so in five distinct stages. Only the first two of these stages have been investigated in any detail, according to Lakshmi, because the remaining stages are relatively unstable and quickly change.

To understand the more unstable stages of the process, scientists need advanced scientific tools that can probe these complex systems at the atomic level.

For this research, Lakshmi and her colleagues trapped three different species of photosystem II in one of the more unstable stages of the process - the third stage in the oxygen-evolving complex called photochemical S2 intermediate - by using low-temperature illumination of photosystem II. They then analyzed the system using an advanced spectroscopic technique called two-dimensional hyperfine sub-level correlation spectroscopy.

The tool detects the weak magnetic interactions in the catalytic site to uncover the structure and activation of the substrate water molecules in the S2 intermediate of photosystem II.

The technology, found in few labs in the world, according to Lakshmi, identified four important groups of hydrogen atoms arising from substrate water molecules within the oxygen-evolving complex. This is a significant step in determining the fate of the water molecules in the solar water oxidation reaction that occurs within photosystem II, Lakshmi said.

"Water is a very stable molecule and it takes four photons of light to split water," she said. "This is a challenge for chemists and physicists around the world as the four-photon reaction has very stringent requirements."

The article published in the Royal Society of Chemistry journal Energy and Environmental Science can be found here.

.


Related Links
Rensselaer Polytechnic Institute (RPI)
Darwin Today At TerraDaily.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





FLORA AND FAUNA
American man critical after chimpanzee mauling in S.Africa
Johannesburg (AFP) June 29, 2012
An American research student was in a critical condition in a South African hospital on Friday after he was dragged by chimpanzees into an enclosure at a primate sanctuary and attacked. The mauled body of the student, identified in local media as Andrew Oberle, was retrieved from the enclosure by paramedics under armed guard at the Jane Goodall Institute Chimp Eden near the eastern town of N ... read more


FLORA AND FAUNA
Jakarta, Canberra boost asylum cooperation

Google urges governments to share disaster data

20 killed as fuel truck crash in China sparks fire

Record radiation levels detected at Fukushima reactor

FLORA AND FAUNA
Deep-sea rare earths found in Japan

Toshiba fined in US antitrust case

Tablet PCs poised to take over PC market

SACLA draws acclaim for unique XFEL design

FLORA AND FAUNA
Britain's urban rivers bounce back

China fishermen sue US firm for oil spill: lawyer

EU underpays Madagascar for access to fish

India's monsoon seen picking up after slow start

FLORA AND FAUNA
Argentina court upholds glacier protections against mining

Study: Wrong diet doomed 1912 polar try

Scientists to produce first 3-D models of Arctic sea ice

Canada builds up arctic region defenses

FLORA AND FAUNA
Vertical farm in abandoned pork plant turns waste into food

Screening horticultural imports: New models assess plant risk through better analysis

Scientists urge new approaches to plant research

Want bigger plants? Get to the root of the matter

FLORA AND FAUNA
Nine killed, four missing in Turkey floods

Northeast India floods kill 79, displace two million

Shallow 6.3-magnitude quake hits northwest China

Floods swamp eastern India, 1.3 million displaced

FLORA AND FAUNA
S.African game farmer jailed for 8 years over rhino horn

Chimpanzees cleared after mauling American in S.Africa: park

Rwanda gorillas prosper despite guerrillas next door

Kenyan army hunts kidnappers of four foreign aid workers

FLORA AND FAUNA
Seabirds studied for clues to human aging

Hong Kong's land shortage forces bereaved to sea

Diet of early human relative Australopithecus shows surprises

Outside View: 18th-century words for today




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement