Cyanobacteria and plants carry out oxygenic photosynthesis. They use water to generate the atmospheric oxygen we breathe and carbon dioxide to produce the biomass serving as food, feed, fibre and fuel. This paper scans the emergence of structural and mechanistic understanding of oxygen evolution over the past 50 years. It reviews speculative concepts and the stepped insight provided by novel experimental and theoretical techniques. Driven by sunlight photosystem II oxidizes the catalyst of water oxidation, a hetero-metallic Mn4CaO5(H2O)4 cluster. Mn3Ca are arranged in cubanoid and one Mn dangles out. By accumulation of four oxidizing equivalents before initiating dioxygen formation it matches the four-electron chemistry from water to dioxygen to the one-electron chemistry of the photo-sensitizer. Potentially harmful intermediates are thereby occluded in space and time. Kinetic signatures of the catalytic cluster and its partners in the photo-reaction centre have been resolved, in the frequency domain ranging from acoustic waves via infra-red to X-ray radiation, and in the time domain from nano- to milli-seconds. X-ray structures to a resolution of 1.9 Å are available. Even time resolved X-ray structures have been obtained by clocking the reaction cycle by flashes of light and diffraction with femtosecond X-ray pulses. The terminal reaction cascade from two molecules of water to dioxygen involves the transfer of four electrons, two protons, one dioxygen and one water. A rigorous mechanistic analysis is challenging because of the kinetic enslaving at millisecond duration of six partial reactions (4e−, 1H+, 1O2). For the time being a peroxide-intermediate in the reaction cascade to dioxygen has been in focus, both experimentally and by quantum chemistry. Homo sapiens has relied on burning the products of oxygenic photosynthesis, recent and fossil. Mankind's total energy consumption amounts to almost one-fourth of the global photosynthetic productivity. If the average power consumption equalled one of those nations with the highest consumption per capita it was four times greater and matched the total productivity. It is obvious that biomass should be harvested for food, feed, fibre and platform chemicals rather than for fuel.

中文翻译：

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有氧光合作用：历史、现状和前景

蓝藻和植物进行有氧光合作用。他们使用水来产生我们呼吸的大气中的氧气和二氧化碳来生产用作食物、饲料、纤维和燃料的生物质。本文回顾了过去 50 年来对氧气演化的结构和机制理解的出现。它回顾了新的实验和理论技术提供的推测性概念和阶梯式洞察力。在阳光光系统 II 的驱动下，氧化水氧化催化剂，一种异金属锰4氧化钙5（H2○）4簇。锰3Ca 排列成立方体，一个 Mn 悬垂出来。通过在开始形成分子氧之前累积四种氧化当量，它使从水到分子氧的四电子化学与光敏剂的单电子化学相匹配。潜在有害的中间体因此在空间和时间上被封闭。在从声波到红外线到 X 射线辐射的频域以及从纳秒到毫秒的时域中，催化簇及其在光反应中心的伙伴的动力学特征已经得到解决。可提供分辨率为 1.9 Å 的 X 射线结构。通过闪光和飞秒 X 射线脉冲衍射对反应周期进行计时，甚至可以得到时间分辨的 X 射线结构。从两个水分子到分子氧的末端反应级联涉及四个电子、两个质子、一个分子氧和一个水的转移。严格的机理分析具有挑战性，因为六个部分反应（4e-, 1H+, 1O2）。目前，在生成分子氧的级联反应中，过氧化物中间体一直是实验和量子化学的焦点。智人依靠燃烧含氧光合作用的产物，最近的和化石的。人类的总能源消耗量几乎占全球光合生产力的四分之一。如果平均电力消耗等于人均消耗量最高的国家之一，那么它会高出四倍，并且与总生产力相匹配。很明显，生物质应该被用作食物、饲料、纤维和平台化学品，而不是燃料。