EFFECTS OF pH AND THE COMPONENTS OF BICARBONATE AND PHOSPHATE BUFFERED SOLUTIONS ON THE METABOLISM OF POTATO DISCS AND THEIR ABILITY TO ABSORB IONS

Abstract

The effects of pH and of concentration of a KHCO3H2CO3 buffer system on the absorption of bromide and on the metabolism of potato discs were investigated. The effects of the treatments on bromide absorption, pro-tein synthesis, and oxidations in the tissue catalyzed by oxidases (phenolases) are closely parallel. At constant pH, increasing the external conc. of KHCO3 and dissolved CO2 depresses (and eventually suppresses) both protein synthesis and bromide .10 lmimIiMosi. Tiin h a broad range, in the absence of added bicarbonate, in which bromide accumulation is not much affected by pH. 3-dimensional figures are presented to show the behavior of the tissue (bromide uptake, N metabolism, etc.) as influenced by pH and conc. of a bicarbonate buffer. Respiration, protein synthesis and bromide accumulation are closely linked. Tissue in which neither bromide accumulation nor protein synthesis oc-curred could still accumulate K from relatively strong bi-carbonate solns. The accumulation of K under these conditions was less dependent on processes of growth than when a cation and non-reactive anion were accumulated simultaneously. Phosphate and bicarbonate buffered solns. were compared and despite different specific effects, the paral-lelism between respiration and protein synthesis is consistently maintained. Brief reference is made to the general problem of the effect of pH on respiration and to dis-crepancies in the literature.