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Ion Behavior in Yeast. III. Specificity, Anomalous Cation Efflux, and Role of Metabolism
Author(s) -
Olsen R. A.
Publication year - 1969
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1969.03615995003300030024x
Subject(s) - efflux , yeast , chemistry , ion , membrane potential , biophysics , membrane , ion transporter , saccharomyces cerevisiae , cell membrane , biochemistry , biology , organic chemistry
In this communication we consider a simple and novel hypothesis for preferential efflux of Na + and H + from the yeast cell ( Saccaromyces cerevisiae Meyer ex Hansen) against an apparent electrochemical potential gradient. Attention is centered upon the peripheral membrane of the cell which is of high lipid content and of correspondingly low dielectric constant. As respiration proceeds, waste products X ‐ (predominantly succinate) continuously move from the cell via the membrane, thereby unavoidably providing a driving force for cation efflux. The accompanying cations are considered to form undissociated ion pairs with X ‐ in the membrane. Coulombic attraction accordingly favors the smaller cation and is presumed to account for the specificity for Na + over K + , e.g., in the efflux process. The hypothesis thereby accounts for anomalous ion behavior without postulation of specially endowed transport pumps and without expenditure of energy by the cell.