The escape of Tritonia: dynamics of a neuromuscular control mechanism.

The results of photosynthesis experiments with ¹⁸O labelled water and carbon dioxide are commonly regarded as the strongest arguments for a light-induced water oxidation. In these experiments, however, several sources of error have not been adequately considered. The peculiarities of natural H₂OCO₂ mixtures and their enzymatically enhanced equilibration are discussed. The unequal distribution of the oxygen isotopes is considered. Relevant data are presented on the CO₂ storage in green plant cells and the oxygen burst which is often observed during the beginning of the light period. After the statement of the necessary precautions for isotope experiments data of former measurements of the oxygen isotope discrimination by photosynthetic and respiratory processes are discussed. The data laid down in the literature together with the results of some experiments with deuterated water are taken as disproof of the hypothesis of water oxidation.