Solar energy conversion by photosystem II: principles and structures

Abstract

Photosynthetic water oxidation by Photosystem II (PSII) is a fascinating process because it sustains life on Earth and serves as a blue print for scalable synthetic catalysts required for renewable energy applications. The biophysical, computational, and structural description of this process, which started more than 50 years ago, has made tremendous progress over the past two decades, with its high-resolution crystal structures being available not only of the dark-stable state of PSII, but of all the semi-stable reaction intermediates and even some transient states. Here, we summarize the current knowledge on PSII with emphasis on the basic principles that govern the conversion of light energy to chemical energy in PSII, as well as on the illustration of the molecular structures that enable these reactions. The important remaining questions regarding the mechanism of biological water oxidation are highlighted, and one possible pathway for this fundamental reaction is described at a molecular level.

Contribution Factors of the First Kind Calculated for the Marcus Electron-Transfer Rate and Their Applications

“…1,2 The most important aspect of photosynthesis is that plants and other terrestrial organisms absorb sunlight, take up carbon dioxide (CO 2 ), and produce oxygen (O 2 ). This is in complete contrast to animals, which inhale O 2 and exhale CO 2 according to the following reaction equation: 3,4…”

“…Currently, photosynthesis is one of the most investigated research fields in various scientific disciplines. , The most important aspect of photosynthesis is that plants and other terrestrial organisms absorb sunlight, take up carbon dioxide (CO 2 ), and produce oxygen (O 2 ). This is in complete contrast to animals, which inhale O 2 and exhale CO 2 according to the following reaction equation: , 6 CO 2 + 12 H 2 O + light → C 6 H 12 O 6 + 6 O 2 + 6 H 2 O Although the photosynthesis chemical reaction appears simple, it microscopically comprises numerous complex processes, which are difficult to elucidate using even state-of-the-art technology.…”

Reaction Center Excitation in Photosystem II: From Multiscale Modeling to Functional Principles

“…Key light-dependent photosynthetic processes take place in an array of transmembrane proteins that work in tandem to generate the proton motive force that drives ATP synthesis. In oxygenic photosynthesis the photosynthetic cascade is initiated at Photosystem II (PSII), a dimeric multisubunit pigment–protein complex that uses light to catalyze water oxidation into molecular oxygen and supply reducing equivalents further along the chain . A PSII monomer is composed of 20 subunits.…”

Going around the Kok cycle of the water oxidation reaction with femtosecond X-ray crystallography

“…In natural photosynthesis, the light-driven splitting of water into electrons, protons and molecular oxygen forms the first step of the solar-to-chemical energy conversion process (Shevela et al, 2023;Cox et al, 2013). The reaction takes place in photosystem II (PS II; Fig.…”