Influx Isotherms — their Interpretation and Use

Abstract

Since the shapes of influx isotherms are being accepted as evidence for two (or more) transport processes involved in influx to plant cells, and since parameters of curves fitted to isotherms are being used as fundamental characteristics of transport systems, it is becoming important to examine critically whether these interpretations of influx data are valid. The necessity for such a reappraisal is most strikingly apparent when one considers the possible ways of identifying isolated transport machinery. If the shape of the isotherm is not sufficient to distinguish or characterise transport processes it will not be profitable to attempt to identify transport machinery amongst microsomal fractions by a response to changing concentrations of the transported substance.