PH oscillations in transport processt

Abstract

Oscillations in pH have been observed when a substrate passes through a synthetic membrane containing enzymes which possess the autocatalytic character in pH. In this paper, we present a mathematical model and computations to show the role of buffer on the oscillation. The theory shows that the oscillation strongly depends on the buffer concentration, in agreement with the experimental observation. In addition, we have found that depending on the nature of a buffer, a buffer can either enhance or suppress the oscillation. We have also shown that in the absence of buffer, oscillations in the papain-BAEE system which corresponds to those observed by Naparstek et al. arise only if the diffusion constant of OH − is at least 25 times larger than that measured by the experiment. An explanation for this discrepancy is given in this paper.