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Calcium peroxide or calcium dioxide is the inorganic compound with the formula CaO 2. It is the peroxide (O 2 2−) salt of Ca 2+. Commercial samples can be yellowish, but the pure compound is white. It is almost insoluble in water. [3]
The oxygen-evolving complex is the site of water oxidation. It is a metallo-oxo cluster comprising four manganese ions (in oxidation states ranging from +3 to +4) [6] and one divalent calcium ion. When it oxidizes water, producing oxygen gas and protons, it sequentially delivers the four electrons from water to a tyrosine (D1-Y161) sidechain ...
S 4 reacts with water producing free oxygen: 2 H 2 O → O 2 + 4 H + + 4 e −. This conversion resets the catalyst to the S 0 state. The active site of the OEC consists of a cluster of manganese and calcium with the formula Mn 4 Ca 1 O x Cl 1–2 (HCO 3) y. This cluster is bound to D 1 and CP 43 subunits and stabilized by peripheral membrane ...
Light-dependent reactions of photosynthesis at the thylakoid membrane. Light-dependent reactions are certain photochemical reactions involved in photosynthesis, the main process by which plants acquire energy. There are two light dependent reactions: the first occurs at photosystem II (PSII) and the second occurs at photosystem I (PSI).
In general outline, photosynthesis is the opposite of cellular respiration: while photosynthesis is a process of reduction of carbon dioxide to carbohydrates, cellular respiration is the oxidation of carbohydrates or other nutrients to carbon dioxide. Nutrients used in cellular respiration include carbohydrates, amino acids and fatty acids.
This occurs by oxidation of water in the case of oxygenic photosynthesis. The electron-deficient reaction center of photosystem II (P680*) is the strongest biological oxidizing agent yet discovered, which allows it to break apart molecules as stable as water. [4] The water-splitting reaction is catalyzed by the oxygen-evolving complex of ...
The reaction is part of the light-dependent reactions of photosynthesis in cyanobacteria and the chloroplasts of green algae and plants. It utilizes the energy of light to split a water molecule into its protons and electrons for photosynthesis. Free oxygen, generated as a by-product of this reaction, is released into the atmosphere.
Water oxidation catalysis (WOC) is the acceleration (catalysis) of the conversion of water into oxygen and protons: 2 H 2 O → 4 H + + 4 e − + O 2. Many catalysts are effective, both homogeneous catalysts and heterogeneous catalysts. The oxygen evolving complex in photosynthesis is the premier example. There is no interest in generating ...