Philip Cash

Document Type

Honors Project

First Advisor

Dr. Joseph Crockett

Degree Award Date

Spring 2000


Cation Size, Inhibition, Acid Phosphatase


Analytical Chemistry | Chemistry | Laboratory and Basic Science Research


The effect of cation size on the enzymatic reaction of acid phosphatase with PNPP was further examined using the Hanes transformation of the Michaelis-Menten equation of enzyme kinetics. A series of six divalent metals (M2+) - barium, cadmium, calcium, cobalt, copper, and strontium as nitrate salts - were tested using this method to obtain the values of KM and V max for the reaction when the metal was present in the reaction mixture. The difference between the value of V max for the inhibited reaction and the value when not inhibited yielded how the metal affected the reaction's velocity. Data obtained showed that there was little effect of ion radius on V max, and virtually no affect of the radius on KM. There is, however, a decreasing trend of binding affinity as cationic radius increases. Future studies will look at the affect other cations and anions in terms of differing charge and structure.