The significance of kinetic constants

The derivation using the steady-state assumptions shows that  

It would appear, therefore, that the view of the Michaelis-Menten situation envisaged by Briggs and Haldane is a special case in which kf2 is so much smaller than Arl that the value of the ratio is negligible compared with K s and  

The apparent dissociation constant may be treated as an overall dissociation constant for much more complex situations involving several linked rate constants °. 

According to the interpretation of the two-step mechanism offered above, the definition of Kmax reflects the fact that the decomposition of the ES complex is rate limiting so that when all the enzyme is in the form of ES a maximum rate will be observed, i.e. ES - ,o,- 

It is also feasible that, following changes in the value of Kmax under different reaction conditions, it might be possible to obtain information concerning the kinetics of the rate-limiting step in the decomposition of ES. The catalytic constant or turnover number ( , ) is a first-order rate constant that refers to the properties and reactions of the enzyme-substrate, enzyme-intermediate, and enzyme-product complexes. The units of kca, are time , and l/k t is the time required to turn over a molecule of substrate on an active site. 

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