Micelles Michaelis-Menten equation

The quantitative treatment of kinetic data is based on the pseudophase separation approach, i.e. the assumption that the aggregate constitutes a (pseudo)phase separated from the bulk solution where it is dispersed. Some of the equations below are reminiscent of the well-known Michaelis- Menten equation of enzyme kinetics [101]. This formal similarity has led many authors to draw a parallel between micelle and enzyme catalysis. However, the analogy is limited because most enzymatic reactions are studied with the substrate in a large excess over the enzyme. Even for systems showing a real catalytic behavior of micelles and/or vesicles, the above assumption of the aggregate as a pseudophase does not allow operation with excess substrate. The condition... 

The classical Michaelis-Menten equation is also obeyed in reverse micelles for the simple case of unimolecular reactions. Because the enzyme concentration is low compared to reverse micelle concentration, model 1 of Table 26.3 should be... 

The kinetics of enzymatic reactions in microemulsions obey, as a rule, the classic Michaelis-Menten equation [6,26,35], but difhculties arise in interpreting the results because of the distribution of reactants, products, and enzyme molecules among the microphases of the microemulsion [8,36-38], In addition, there are some enzymes in reverse micelles that exhibit enhanced activity as compared to that expressed in water this has given rise to the concept of superactivity [6,26,39], The superactivity has been explained in terms of the state of water in reverse micelles, the increased rigidity of the enzymes caused by the surfactant layer, and the enhanced substrate concentration at the enzyme microenvironment [36,40],... 

The mechanisms of micelle-catalyzed reactions have been studied not only by analogy with the Michaelis-Menten equation for enzymatic reactions but also from the perspective of volume fractions of the two-part reaction system consisting of the micelles and the intermicellar bulk solutions.The kinetics of this reaction has been successfully used only when the micellar concentrations are much higher than the reactant concentrations. However, micellar concentrations near the CMC are often less than the reactant concentrations. In such cases, the distribution of reactants among micelles must be taken into consideration, which is essentially a thermodynamic problem (Chapter 9). Reactant is a better technical term than substrate for micelle-catalyzed reactions. 

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