Ion Behavior in Yeast. I. The Cell as an Exchanger System1
- R. A. Olsen and
- S. Tripp2
In this investigation a simple hypothesis is considered for partially explaining the behavior of alkali cations in the yeast cell (Saccharomyces cerevisiae Meyer ex Hansen). The cell interior is viewed as a metabolically-derived matrix containing cation exchange sites. The accumulation of cations against a marked concentration gradient is thereby made possible. The exchange sites tend to buffer the cell composition with respect to changes in composition of the ambient solution, thereby providing a simple explanation for homeostasis. The model provides an explanation for the observed coupling between K+ influx and Na+ efflux by attributing it to an exchange process. Approximately half of the cellular volume is shown to consist of an outer space into which ions can passively equilibrate from the ambient solution. The peripheral membrane is accordingly viewed as an ion-permeable barrier.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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