. Electrolytes in biological systems, incorporating papers presented at a symposium at the Marine Biological Laboratory in Woods Hole, Massachusetts, on September 8, 1954 . JU. .Hi Ac ds (b) Bases Fig. 3. Micellar model of weak electrolyte distribution, a: Osterhout's model of the steady state distribution of a weak acid, pKa 4, across a cell membrane separating two solutions of difTerent pH, the cell membrane being freely permeable to the unionized moiety, b: A trans- port micelle whose interior pH differs from that of the external bulk solution and of whose boundaries that on the left is fre
. Electrolytes in biological systems, incorporating papers presented at a symposium at the Marine Biological Laboratory in Woods Hole, Massachusetts, on September 8, 1954 . JU. .Hi Ac ds (b) Bases Fig. 3. Micellar model of weak electrolyte distribution, a: Osterhout's model of the steady state distribution of a weak acid, pKa 4, across a cell membrane separating two solutions of difTerent pH, the cell membrane being freely permeable to the unionized moiety, b: A trans- port micelle whose interior pH differs from that of the external bulk solution and of whose boundaries that on the left is freely permeable to unionized particles (light arrow) and that on the right is equallj' permeable to both unionized and ionized (dark arrow) particles. The movement and distribution across the left boundarj^ would correspond to the oil barrier of a developing a concentration gradient while the free movement across the right boundary would tend to dissipate the concentration dififerences developing on the left, such that weak acids would be pumped from right to left and weak bases from left to right. opposite face of the micelle which does not discriminate between ionized and unionized particles, there will be net movement tending to dissipate the con- centration difference building up across the other face. The overall result will be a continued pumping of weak electrolyte from one side of the epithelium to the other and the energy for the uphill transfer will come from the maintenance of the distinctive pH within the micelle. In two instances, carbonic and lactic acids, there is a net movement from the secretory to the nutrient solution independent of the pH of the bulk bathing solutions. The secretion of weak electrolytes by the dog stomach is compatible
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Keywords: ., bookcentury1900, booksubjectelectrolytes, booksubjectphysiologyc
