The ratio of K(39) / K(41) appears to be lower in the sap of Valonia and Nitella than in the environment, indicating that the living cell can separate these isotopes to some extent. Experiments with a mixture of guaiacol and p-cresol suggest that a similar separation may occur here but further experiments are needed.
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http://dx.doi.org/10.1085/jgp.23.6.741 | DOI Listing |
J Gen Physiol
November 1943
Laboratories of The Rockefeller Institute for Medical Research, New York, and The Marine Biological Laboratory, Woods Bole.
In Nitella, Chara, Hydrodictyon, and Valonia the inner and outer non-aqueous protoplasmic surface layers can be separated by certain plasmolytic agents which penetrate the outer surface more rapidly than the inner and hence raise the osmotic pressure of the protoplasm lying between them and cause it to increase in thickness by taking up water from the central vacuole. We may therefore conclude that the two surfaces differ. This idea is confirmed by earlier electrical measurements which show that when sap is placed outside the cell the chain See PDF for Structure produces an E.
View Article and Find Full Text PDFThe ratio of K(39) / K(41) appears to be lower in the sap of Valonia and Nitella than in the environment, indicating that the living cell can separate these isotopes to some extent. Experiments with a mixture of guaiacol and p-cresol suggest that a similar separation may occur here but further experiments are needed.
View Article and Find Full Text PDFValues have been calculated for apparent mobilities and partition coefficients in the outer non-aqueous layer of the protoplasm of Nitella. Among the alkali metals (with the exception of cesium) the order of mobilities resembles that in water and the partition coefficients (except for cesium) follow the rule of Shedlovsky and Uhlig, according to which the partition coefficient increases with the ionic radius. Taking the mobility of the chloride ion as unity, we obtain the following: lithium 2.
View Article and Find Full Text PDFIn Nitella, as in Halicystis, guaiacol increases the mobility of Na(+) in the outer protoplasmic surface but leaves the mobility of K(+) unaffected. This differs from the situation in Valonia where the mobility of Na(+) is increased and that of K(+) is decreased. The partition coefficient of Na(+) in the outer protoplasmic surface is increased and that of K(+) left unchanged.
View Article and Find Full Text PDFIn Nitella the substitution of KCl for NaCl changes the P.D. in a negative direction.
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