ION-EXCHANGE SELECTIVITIES OF AMINO-ACIDS FOR THE AMMONIUM ION ON PERIDERM AND CUTICULAR MEMBRANES

The selectivity coefficients of some neutral amino acids for the ammonium form of potato periderm and pear fruit cuticular membranes were determined, using the mass action law, and were found to be correlated with various physicochemical parameters. Relationships were obtained between selectivity coefficients and physicochemical parameters such as the partial molar volume and molecular weight. The results show that the selectivity coefficient value increases with an increase in molecular size and partial volume of the amino acids through extension of the hydrophobic-CH2-group.