Michaelis-Menten equation simple steady state kinetics

Simple steady state kinetics and Michaelis-Menten equation... 

This reaction cycle has more steps than the simple Michaelis-Menten scheme. Nonetheless, the steady-state rate equations describing these reaction cycles have indistinguishable functions, and one cannot determine the number of intermediary steps by steady-state kinetics alone. 

Under typical experimental conditions, the enzyme system is saturated with O2 and H+. Thus this enzyme system includes four substrates and four products. However, the initial steady state kinetics of this enzyme system obeys a simple Michaelis-Menten equation (a rectangular hyperbolic relation) for each kinetic phase of the two phases at low and high ferrocytochrome c concentrations as described above. This result indicates that the four ferrocytochromes c react with the enzyme in a ping-pong fashion in each substrate concentration range. That is, each ferroferrocytochrome c reacts with the enzyme after the previous cytochrome c in the oxidized state is released from the enzyme. Cytochrome c... 

Under certain conditions the steady state has the form of the Michaelis-Menten equation (Section 9.1.2). Nevertheless, the equation for APase contains more factors than that of the simple reaction given in Section 9.1.2. For detailed kinetic considerations, Fernley (1971) and Reid and Wilson (1971) should be consulted. The simplified representation of Fig. 10.3 is also often complicated by other parameters e.g. only one active site per dimer seems to be active for the bacterial enzyme at low substrate coneentrations (<10" M), whereas at higher concentrations both sites are active. Substrate activation, at high substrate concentrations (>10" M), was noted by Heppel et al. (1962) but not at high ionic strength (Simpson and Vallee, 1970). 

The Michaelis-Menten equation (8.8) and the irreversible Uni Uni kinetic scheme (Scheme 8.1) are only really applicable to an irreversible biocatalytic process involving a single substrate interacting with a biocatalyst that comprises a single catalytic site. Hence with reference to the biocatalyst examples given in Section 8.1, Equation (8.8), the Uni Uni kinetic scheme is only really directly applicable to the steady state kinetic analysis of TIM biocatalysis (Figure 8.1, Table 8.1). Furthermore, even this statement is only valid with the proviso that all biocatalytic initial rate values are determined in the absence of product. Similarly, the Uni Uni kinetic schemes for competitive, uncompetitive and non-competitive inhibition are only really applicable directly for the steady state kinetic analysis for the inhibition of TIM (Table 8.1). Therefore, why are Equation (8.8) and the irreversible Uni Uni kinetic scheme apparently used so widely for the steady state analysis of many different biocatalytic processes A main reason for this is that Equation (8.8) is simple to use and measured k t and Km parameters can be easily interpreted. There is only a necessity to adapt catalysis conditions such that... 

This textbook for advanced courses in enzyme chemistry and enzyme kinetics covers the field of steady-state enz5mie kinetics from the basic principles inherent in the Michaelis-Menten equation to the expressions that describe the multi-substrate enzyme reactions. The purpose of this book is to provide a simple but comprehensive framework for the study of enzymes with the aid of kinetic studies of enzyme-catalyzed reactions. The aim of enzyme kinetics is twofold to study the kinetic mechanism of enz5mie reactions, and to study the chemical mechanism of action of enzymes. 

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