Effect of the medium pH and the cell pH upon the kinetical parameters of phosphate uptake by yeast

Abstract

1. 1. Both the maximum rate of phosphate uptake and the K m depend upon the pH of the medium in a complex way. 2. 2. The effect of medium pH upon the maximum rate of uptake is mainly indirect and is correlated with changes in cell pH. 3. 3. The K m is affected by the medium pH both directly via an apparent competitive inhibition by hydroxyl anions and indirectly in a similar ways as the maximum rate of uptake.