K. G. TALK AND G. McGUIRE 



601 



potato sucrase.^ The exact optimum pH is difficult to determine 

 in any case because of the flat portion of the curve, but with soluble 



3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 pH 



Fig. 1. Action of soluble banana sucrase preparation at different hydrogen ion 

 concentrations on sucrose. 



banana sucrase it is not far removed from 4.0 at 35°C. for 1\ hours 

 action. The method of presenting these results is not the most 

 satisfactory but it shows definitely the optimum conditions. Not 



