ISSN:
1615-6102
Keywords:
Endosmosis
;
Ion movement
;
Membrane depolarization
;
Nitella
;
Transcellular osmosis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Movements of K+, Na+, and Cl}- ions during transcellular osmosis were studied in internodal cells ofNitella flexilis. Much K+ was released from the endosmotic cell part, but only a little from the exosmotic cell part. The amount of K+ released depended on the osmotic gradient driving transcellular osmosis. Movement of Na+ was hardly detected. Cl}- was released in nearly the same amounts as K+. Release of K+ from the endosmotic cell half was stimulated remarkably by lowering the temperature from 20 to 1 °C, and also by lowering the internal osmotic pressure but inhibited by raising it. The dependence of K+ release on osmotic gradient, internal osmotic pressure and temperature can be explained by their effects on membrane depolarization and membrane resistance (Hayama et al. 1978). We concluded thatP K remained unchanged, whileP Cl increased a great deal in the endosmotic cell part.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01275733
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