Abstract
Three intracellular compartments for potassium exchange have been observed in intact cells of the giant-celled alga, Nitella axillaris. These compartments have been compared with the exchange properties of isolated subcellular structures. The smallest and fastest compartment (apparent half-time, 23 seconds) appears to involve passive absorption on the cell wall. The next largest (apparent half-time, 5 hours) may represent exchange with the cytoplasmic layer through the plasma membrane, the chloroplasts being in rapid equilibrium with the surrounding cytoplasm. The largest and slowest compartment (apparent half-time, 40 days) has been identified with the central vacuole. The vacuolar membrane and the plasma membrane have similar properties with respect to K permeability. Thus, the experimental data from the whole cell can be accounted for by a structural model of the compartments. Cyanide in concentrations up to 10-3 M causes no net loss of K. The fastest compartment in Nitella and in higher plants is compared, and the ecological significance of the slow rate of potassium transport in Nitella is discussed.
Full Text
The Full Text of this article is available as a PDF (965.0 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- BENNETT M. C., RIDEAL E. Membrane behaviour in Nitella. Proc R Soc Lond B Biol Sci. 1954 Sep 27;142(909):483–496. doi: 10.1098/rspb.1954.0038. [DOI] [PubMed] [Google Scholar]
- COWIE D. B., ROBERTS R. B., ROBERTS I. Z. Potassium metabolism in Escherichia coli; permeability to sodium and potassium ions. J Cell Physiol. 1949 Oct;34(2):243–257. doi: 10.1002/jcp.1030340205. [DOI] [PubMed] [Google Scholar]
- GAFFEY C. T., MULLINS L. J. Ion fluxes during the action potential in Chara. J Physiol. 1958 Dec 30;144(3):505–524. doi: 10.1113/jphysiol.1958.sp006116. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HODGKIN A. L., KEYNES R. D. The mobility and diffusion coefficient of potassium in giant axons from Sepia. J Physiol. 1953 Mar;119(4):513–528. doi: 10.1113/jphysiol.1953.sp004863. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Higinbotham N., Hanson J. The Relation of External Rubidium Concentration to Amounts and Rates of Uptake by Excised Potato Tuber Tissue. Plant Physiol. 1955 Mar;30(2):105–112. doi: 10.1104/pp.30.2.105. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MACROBBIE E. A., DAINTY J. Ion transport in Nitellopsis obtusa. J Gen Physiol. 1958 Nov 20;42(2):335–353. doi: 10.1085/jgp.42.2.335. [DOI] [PMC free article] [PubMed] [Google Scholar]
- OSTERHOUT W. J. V. Some bioelectrical problems. Proc Natl Acad Sci U S A. 1949 Oct;35(10):548–558. doi: 10.1073/pnas.35.10.548. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SCOTT G. T., HAYWARD H. R. Metabolic factors influencing the sodium and potassium distribution in Ulva lactuca. J Gen Physiol. 1953 May;36(5):659–671. doi: 10.1085/jgp.36.5.659. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SCOTT G. T., HAYWARD H. R. The influence of temperature and illumination on the exchange of potassium ion in Ulva lactuca. Biochim Biophys Acta. 1953 Nov;12(3):401–404. doi: 10.1016/0006-3002(53)90158-9. [DOI] [PubMed] [Google Scholar]
- SOLOMON A. K., LOUCKS J., POLLEN D. A., GILL T. J., 3rd, WOLF E. Search for a potassium compartment in the human red cell membrane. Nature. 1957 Nov 9;180(4593):993–994. doi: 10.1038/180993a0. [DOI] [PubMed] [Google Scholar]
- SOLOMON A. K. The permeability of the human erythrocyte to sodium and potassium. J Gen Physiol. 1952 May;36(1):57–110. doi: 10.1085/jgp.36.1.57. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Scott G. T., DE Voe R., Hayward H., Craven G. Exchange of Sodium Ion in Ulva lactuca. Science. 1957 Jan 25;125(3239):160–160. doi: 10.1126/science.125.3239.160. [DOI] [PubMed] [Google Scholar]
- TOLBERT N. E., ZILL L. P. Photosynthesis by protoplasm extruded from Chara and Nitella. J Gen Physiol. 1954 May 20;37(5):575–588. doi: 10.1085/jgp.37.5.575. [DOI] [PMC free article] [PubMed] [Google Scholar]