منابع مشابه
Transport of ions across cellular membranes.
‘active transport,’ it may be useful to define the term in an unequivocal way. In accordance with Rosenberg (I z I), the term ‘transport’ or ‘active transport’ will be taken to mean a transfer of a substance against a chemical potential gradient. This definition is rather narrow; for instance, cases where a substance is found to pass faster along the concentration gradient than would be expecte...
متن کاملStudy the Transport Properties of Anion and Cation Exchange Membranes toward Various Ions Using Chronopotentiometry
The transport properties of various anion and cation exchange membranes were studied in different electrolyte solutions using chronopotentiometry technique to get insight about the influence of the counter ion on the transport properties of the membranes. The investigated samples include heterogeneous ion exchange membranes varying in the functionality of fixed charged gro...
متن کاملDivalent Ions and the Surface Potential of Charged Phospholipid Membranes
Phospholipid bilayer membranes were bathed in a decimolar solution of monovalent ions, and the conductance produced by neutral carriers of these monovalent cations and anions was used to assess the electric potential at the surface of the membrane. When the bilayers were formed from a neutral lipid, phosphatidylethanolamine, the addition of alkaline earth cations produced no detectable surface ...
متن کاملStabilization and destabilization of cell membranes by multivalent ions.
We propose a mechanism for the stabilization and destabilization of cell membranes by multivalent ions with an emphasis on its implications for the division and fusion of cells. We find that multivalent cations preferentially adsorbed onto a membrane dramatically change the membrane stability. They not only reduce the surface charge density of the membrane but also induce a barrier to pore grow...
متن کاملTransport of Ions and Small Molecules across Cell Membranes
The plasma membrane is a selectively permeable barrier between the cell and the extracellular environment. Its permeability properties ensure that essential molecules such as ions, glucose, amino acids, and lipids readily enter the cell, metabolic intermediates remain in the cell, and waste compounds leave the cell. In short, the selective permeability of the plasma membrane allows the cell to ...
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ژورنال
عنوان ژورنال: Nature
سال: 1971
ISSN: 0028-0836,1476-4687
DOI: 10.1038/234286a0