Reaction sequences from light absorption to the cleavage of water in photosynthesis : Routes, rates and intermediates
The reaction sequence between the primary electron acceptor, the oxidized Chlorophyll-aII, and the terminal electron donor, the water splitting enzyme system S, is being described in the range from nanoseconds to milliseconds. For the cleavage of water Chlorophyll-aII (+) extracts four electrons in...
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Published in | Photosynthesis research Vol. 10; no. 3; p. 453 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Netherlands
01.01.1986
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Online Access | Get more information |
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Summary: | The reaction sequence between the primary electron acceptor, the oxidized Chlorophyll-aII, and the terminal electron donor, the water splitting enzyme system S, is being described in the range from nanoseconds to milliseconds. For the cleavage of water Chlorophyll-aII (+) extracts four electrons in four turnovers from the enzyme system S responsible for the water oxidation. For each extraction the electron is moved step by step along the chain that connects the Chlorophyll-aII center with that of S. Beginning with the transfer from the immediate donor, D1, to Chl-aII (+), the subsequent transfer from D2 to D1 (+) ends in the electron transfer from S to D2 (+). This final act establishes in S the oxidizing equivalent, probably in the form of oxidized manganese. Coupled with these acts is an intrinsic proton release and a surplus charge formation. After the generation of the 4th oxidizing equivalent in a concerted final action the evolution of O2 from water takes place. Correlations between the events are described quantitatively. |
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ISSN: | 0166-8595 1573-5079 |
DOI: | 10.1007/BF00118312 |