Homogeneous and Enzyme Catalysis in a Single-Phase System

Homogeneous and Enzyme Catalysis in a Single-Phase System 

In homogeneous catalysis and biocatalysis the catalyst molecules are present in solution. The reaction rate can therefore be directly determined by the turn over frequency TOT, which is defined as the number of reactant molecules (usually in mol) reacting per active center (amount of catalyst in mol) and time (s). For a batch reactor, we get for a reactant A  

The amount of A converted, that is, the absolute number of passes through the catalytic cycle before the catalyst becomes deactivated is called the turn over number (TON)  

Leonor Michaelis (1875-1947) a German biochemist and physician famous for his work with Maud Menten in enzyme kinetics. He studied medicine, and graduated and received his doctorai degree in 1897. in 1906 he started work as director of the bacterioiogy iab in Beriins Charite hospital, becoming Professor extraordinary at Beriin University in 1908. in 1922 he moved to the University of Nagoya (Japan) as Professor of biochemistry, in 1926 to Johns Hopkins University in Baitimore, and in 1929 to the Rockefeller Institute of Medical Research in New York City, where he retired 1941. 

Formally, the reaction rate of homogeneously catalyzed reactions can often be described by the following simple reaction mechanism  

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