Mechanism behind the electric charges generated by photosynthesis -A step towards artificial photosynthesis

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Photosynthesis requires a mechanism to produce large amounts of chemical energy without losing the oxidative power needed to break down water. A Japanese research team has clarified part of this mechanism, marking another step towards the potential development of artificial photosynthesis. The findings were published on February 27 in the online edition of The Journal of Physical Chemistry Letters.

Photosynthesis requires a mechanism to produce large amounts of chemical energy without losing the oxidative power needed to break down water. A Japanese research team has clarified part of this mechanism, marking another step towards the potential development of artificial photosynthesis. The findings were published on February 27 in the online edition of The Journal of Physical Chemistry Letters.

The team was led by Professor KOBORI Yasuhiro (Kobe University Molecular Photoscience Research Center) and PhD student HASEGAWA Masashi (Graduate School of Science) with Associate Professor MINO Hiroyuki (Nagoya University Graduate School of Science).

During the water-splitting reaction in photosynthesis, plants produce oxygen by converting solar energy into chemical energy, providing the energy source necessary for their survival. This reaction is carried out by a protein complex in chloroplasts (located in leaves) called the photosystem II complex (see figure 1).

In 2015 Professor Kobori’s research team succeeded in analyzing the electronic interactions and 3-dimensional placement of the initial charge separation produced directly after photoreaction in the photosynthetic reaction center of purple bacteria, which do not cause the oxidation potential for water-splitting. However, in the photosystem II complex for higher plants, the configuration of the initial charge separation state was unclear, and it was a mystery as to how it led to an effective water-splitting reaction while retaining the high oxidative power.

Read more at Kobe University

Image: Figure 1. This is the ribbon-like structure of the photosystem II complex (PDB ID: 3ARC). (Credit: Kobe University)