The Kinetics of the Catalyzed Reaction between Two Substrates in a Special Case

1975 ◽  
Vol 53 (5) ◽  
pp. 644-647
Author(s):  
Jaroslav Rybicky
Keyword(s):  
Steady State ◽  
Relative Error ◽  
Rate Equation ◽  
Practical Utility ◽  
Sum Of Products ◽  
Kinetics Of ◽  
Special Case ◽  
Fold Excess

The kinetics of the catalyzed reaction between two substrates is dealt with for the special case in which the product associated with the catalyst cannot be distinguished from the product dissociated from the catalyst. The rate equation in which the yield is a sum of products both associated with and dissociated from the catalyst is derived and its applicability is assessed with respect to the kinetic and concentration conditions. It was found that under steady-state conditions and fast preequilibrium condition a twenty-fold excess of the substrates over the catalyst is enough for the yield of reaction to be represented by the equation derived with less than 1% relative error, and even for a five-fold excess the equation remains a fairly good approximation. Under such conditions the rate equation can find practical utility.

Comprehensive Kinetic of Defects in a-SI:H

1991 ◽  
Vol 219 ◽  
Author(s):  
David Redfield ◽  
Richard H. Bube
Keyword(s):  
Solar Cells ◽  
Steady State ◽  
Light Intensity ◽  
Rate Equation ◽  
Defect Density ◽  
Microscopic Models ◽  
Dx Center ◽  
Stretched Exponentials ◽  
Kinetics Of ◽  
Insight Into

ABSTRACTLThe introduction of several new principles into the analysis of transition kinetics of metastable defects in a-Si:H has produced substantially improved rate equation for the density of defects as functions of time, light intensity, and temperature. The solution of this equation is stretched exponential (SE) having properties that explain in unifying way many observations of defect properties, including generation and anneal of the defect density in homogeneous films and degradation and anneal of solar cells. Major consequences are found for both the steady-state and transient properties of the defect density and for interpretations of microscopic models of the defects. These properties are also shown to be analogous to those of metastable centers in other materials, particularly the metastable DX center in AlGaAs which offers rare insight into the microscopic origins of stretched exponentials that can be applied to a-Si:H in ways that provide new perspectives on effects of alloying and hydrogen on stability.

Steady-state kinetics of thyroid peroxidase. evidence for a high degree rate equation using the f statistic

1983 ◽  
Vol 15 (9) ◽  
pp. 1195-1200
Author(s):  
Francisco Solano-Muñoz ◽  
JoséL. Iborra ◽  
JoséA. Lozano ◽  
William G. Bardsley
Keyword(s):  
Steady State ◽  
Rate Equation ◽  
Thyroid Peroxidase ◽  
Steady State Kinetics ◽  
High Degree ◽  
Kinetics Of

A COMPARISON BETWEEN THE INITIAL RATE EXPRESSIONS OBTAINED UNDER STRICT CONDITIONS AND THE RAPID EQUILIBRIUM ASSUMPTION USING, AS EXAMPLE, A FOUR SUBSTRATE ENZYME REACTION

2011 ◽  
Vol 10 (05) ◽  
pp. 659-678
Author(s):  
J. M. YAGO ◽  
C. GARRIDO-DEL SOLO ◽  
M. GARCIA-MORENO ◽  
R. VARON ◽  
F. GARCIA-SEVILLA ◽  
...  
Keyword(s):  
Steady State ◽  
Rate Equation ◽  
Initial Rate ◽  
Enzyme Reaction ◽  
Rate Equations ◽  
Steady State Rate ◽  
State Rate ◽  
Rapid Equilibrium ◽  
Kinetics Of ◽  
Substrate Concentrations

The software WinStes, developed by our group, is used to derive the strict steady-state initial rate equation of the reaction mechanism of CTP:sn-glycerol-3-phosphate cytidylyltransferase [EC 2.7.7.39] from Bacillus subtilis. This enzyme catalyzes a reaction with two substrates and operates by a random ordered binding mechanism with two molecules of each substrate. The accuracy of the steady-state rate equation derived is checked by comparing the rate values it provides with those obtained from the simulated progress curves. To analyze the kinetics of this enzyme using the strict steady-state initial rate equation, several curves for different substrate concentrations and different rate constants are generated. A comparison of these curves with the curves obtained from the rapid equilibrium initial rate equation, with different substrate concentration values, serves to analyze how the strict steady-state rate equation values are closer to those of rapid equilibrium rate equations when rapid equilibrium conditions are fulfilled.

Kinetics of catalytic reduction of nitrogen oxide by carbon monoxide on CuO/Al2O3 catalyst

1983 ◽  
Vol 48 (11) ◽  
pp. 3202-3208 ◽  
Author(s):  
Zdeněk Musil ◽  
Vladimír Pour
Keyword(s):  
Carbon Monoxide ◽  
Nitrogen Oxide ◽  
Rate Equation ◽  
Catalytic Reduction ◽  
Zero Order ◽  
Spectroscopic Measurements ◽  
First Order ◽  
Ir Spectroscopic ◽  
Kinetics Of ◽  
Al2o3 Catalyst

The kinetics of the reduction of nitrogen oxide by carbon monoxide on CuO/Al2O3 catalyst (8.36 mass % CuO) were determined at temperatures between 413 and 473 K. The reaction was found to be first order in NO and zero order in CO. The observed kinetics are consistent with a rate equation derived from a mechanism proposed on the basis of IR spectroscopic measurements.

Kinetic analysis of mechanism of intestinal Na+-dependent sugar transport

1985 ◽  
Vol 248 (5) ◽  
pp. C498-C509 ◽  
Author(s):  
D. Restrepo ◽  
G. A. Kimmich
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Sugar Transport ◽  
Enzyme Kinetic ◽  
Steady State Distribution ◽  
State Distribution ◽  
Least Squares Fit ◽  
Coupling Stoichiometry ◽  
Rate Limiting ◽  
Kinetics Of

Zero-trans kinetics of Na+-sugar cotransport were investigated. Sugar influx was measured at various sodium and sugar concentrations in K+-loaded cells treated with rotenone and valinomycin. Sugar influx follows Michaelis-Menten kinetics as a function of sugar concentration but not as a function of Na+ concentration. Nine models with 1:1 or 2:1 sodium:sugar stoichiometry were considered. The flux equations for these models were solved assuming steady-state distribution of carrier forms and that translocation across the membrane is rate limiting. Classical enzyme kinetic methods and a least-squares fit of flux equations to the experimental data were used to assess the fit of the different models. Four models can be discarded on this basis. Of the remaining models, we discard two on the basis of the trans sodium dependence and the coupling stoichiometry [G. A. Kimmich and J. Randles, Am. J. Physiol. 247 (Cell Physiol. 16): C74-C82, 1984]. The remaining models are terter ordered mechanisms with sodium debinding first at the trans side. If transfer across the membrane is rate limiting, the binding order can be determined to be sodium:sugar:sodium.

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