Scientists at the Arizona State University have finally succeeded to capture the first-even picture of photosynthesis in action. That is, they have taken the snapshots of water molecules splitting into electrons, protons and oxygen. Plants perform photosynthesis in the presence of sunlight to produce energy and oxygen, which is crucial for life on our planet.


Unraveling photosynthesis details to help develop artificial systems

Why bother discovering the secrets of water splitting in plants? Petra Fromme, lead author of the study, said her team’s ultimate objective is to unravel the secrets of photosynthesis and obtain molecular movies of biomolecules. It will help them develop artificial systems (perhaps an artificial leaf?) that would be capable of generating energy and oxygen. The study was published in the journal Nature.

The water splitting process occurred about 2.5 billion years ago in Photosynthesis II (PSII). It eventually led to the atmosphere as we know it today, said scientists. Arizona State University’s Center for Bio-Inspired Solar Fuel Production was the leading supporter of the study. A big problem scientists facing today is discovering an inexpensive and efficient catalyst that oxidizes water into hydrogen ions (protons), electrons and oxygen gas.

Plants and photosynthetic bacteria already know this. Researchers want to know the details of how they carry out the process using calcium and manganese. The newly taken snapshots will give them an idea of how the catalyst changes its structure while still working. Once they discover the mechanism, they can design artificial photosynthetic catalysts to produce useful fuels in the presence of sunlight.

Oxygen is produced at a special site in photosynthesis

In the photosynthesis process, oxygen gas is produced at a “special” metal site, which has one calcium atom and four manganese atoms connected together to form a metal cluster. This cluster is linked to PSII, which catalyzes the water splitting process using sunlight. According to Petra Fromme, it takes four light flashes to release one oxygen molecule from two water molecules attached to the metal cluster.

Researchers took these snapshots with the help of the world’s most powerful X-ray laser, which is at the SLAC National Accelerator Laboratory of the Department of Energy.