Amino Acid Transport through Cation Exchange Membranes: Effects of pH on Interfacial Transport

✍ Scribed by Mie Minagawa; Akihiko Tanioka; Patricio Ramı́rez; Salvador Mafé

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 153 KB
• Volume: 188
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1997.4765

✦ Synopsis

ments especially designed to show the effects of pH on the We present a series of experiments especially designed to show interfacial transport of the amino acid (glycine in our case) the effects of pH on the interfacial transport of glycine through a through a cation exchange membrane. Second, we try to cation exchange membrane. The experimental results are exexplain the experimental results by means of an extensive plained qualitatively by using a theoretical model which incorpotheoretical model which incorporates the equilibrium dissorates the equilibrium dissociation equations for the fraction of ciation equations (1, 2) for the fraction of amino acid forms amino acid forms at different pH values, a rate equation for the at different pH values, a rate equation for the interfacial membrane interfacial transport based on the interfacial chemical transport (13) based on the interfacial chemical reaction (or, reaction, and the Nernst-Planck flux equations for the ion transalternatively, the Donnan equilibrium relationship), and the port through the bulk of the membrane. The results appear to indicate that the rate-limiting step in the amino acid transport Nernst-Planck flux equations (14, 15) for the ion transport process could be the rate at which glycine exits the membrane, through the cation exchange membrane. The experimental and they contribute to a better understanding of amino acid permeresults appear to indicate that the rate-limiting step in the ation across charged membranes. ᭧ 1997 Academic Press transport process could be the rate at which glycine exits Key Words: amino acid transport; ion exchange membranes; pH the membrane, and they constitute a step further in the basic dependent interfacial transport; glycine.

understanding of amino acid permeation across charged membranes.