Initial Rate Enzyme Kinetics

Enzyme kinetics studies normally focus on the initial rate of enzymatic reaction. However, the manual operation of steps of the conventional enzyme kinetics method has some drawbacks. Errors can result from the imprecise time control and time necessary for manual changing the reaction cuvettes into and out of the detector. By using the automatic flow-based analytical systems, enzyme kinetics studies can be carried out at real-time initial rate avoiding the potential errors inherent in manual operation. Flow-based systems have been developed to provide rapid, low-volume, and high-precision analyses that effectively replace the many tedious and high volume requirements of conventional wet chemistry analyses. This article presents various arrangements of flow-based techniques and their potential use in future enzyme kinetics applications.

Download Full-text

KINETIC FORMULATION OF THE DENITRIFICATION PROCESS IN SOIL

Canadian Journal of Soil Science ◽

10.4141/cjss79-028 ◽

1979 ◽

Vol 59 (3) ◽

pp. 249-257 ◽

Cited By ~ 26

Author(s):

C. M. CHO ◽

J. G. MILLS

Keyword(s):

Enzyme Kinetics ◽

Maximum Concentration ◽

Initial Rate ◽

Zero Order ◽

Gas Mixture ◽

Disappearance Rate ◽

High Accumulation ◽

Kinetic Formulation ◽

Initial Concentration ◽

Denitrification Process

Kinetic formulation of denitrification process in soil was developed based on a model of competitive Michaelis-Menten type enzyme kinetics. Several values of parameters were chosen to plot the concentrations of NO−3, NO−2, N2O-N and N2-N at various times of incubation under different initial concentrations of NO−3. According to the model the disappearance rate of NO−3 was found to be independent of initial concentration of NO−3 and was nearly constant, similar to zero order rate of disappearance. The initial rate of NO−2 formation was independent of the NO−3 concentration. However, the maximum concentration of NO−2 and the time at which the maximum was found were found to be dependent upon the NO−3 concentration. When there was very little accumulation of NO−2 in the system, the initial rate of N2O formation was found to be independent of NO−3 concentration. However, if there was high accumulation of NO−2, the initial rate of N2O formation became inversely related to NO−3 concentration. The initiation of N2 formation was generally slower as the concentration of NO−3 increased. The composition of gas mixture, N2O and N2, was found to vary depending upon the initial NO−3 concentration and with the time of incubation. The formulation presented herein describes the features of denitrification experimentally observed fairly well.

Download Full-text