The calorimetric analysis of urea-urease system

Abstract

In the present experiment the temperature change in the reaction system with time was measured in order to investigate the reaction rate continuously and the reaction heats of the urea-urease reaction by using the calorimeter. The heats of reaction were endothermic theoretically, but NH_3 and CO_2 produced as result of the reaction generated the heats such as heats of dissolution and heat of neutralization. Then the reaction was exothermic in resultant. It was found that the Michaelis-Menten law was obeyed accurately up to a certain concentration of urea, but at high concentration of it there was some falling-off of the rate as in the former experiment. The Michaelis constants were also determined by using the Dixon's method.