Utilisation of binding energy

If the enzyme is rigid and remains undistorted during the catalytic process the 

Although the kinetics of binding may control the reaction if enzyme complementarity is too good and the mobility of the enzyme is too restricted, this is unlikely to be a general situation. Even if, because of weak binding, the rate of dissociation of an initially formed enzyme-substrate complex was fast, say 10 /sec, there is still plenty of time for conformational changes which may take place in less than 10 ° sec. This is compatible with those enzyme-catalysed reactions where the rate-limiting step is diffusion-controlled encounter of the enzyme and substrate. 

The idea that enzymes should not stabilise the substrate too much upon binding is sometimes interpreted to mean that the substrate should be destabilised in the ES complex. This is illustrated in Fig. 9 where the energy of the ES complex is raised by some unspecified mechanism which has the effect of increasing but has no effect upon Such an enzyme would be more effective above saturation but would 

The ground state electron distribution of an isolated molecule invariably determines the type of charge with which it favourably interacts. For example, a carbonyl group would be stabilised by an electron acceptor adjacent to the carbonyl oxygen while it would be energetically favourable to have an electron donor near the carbonyl carbon (XVI). The ground state charge distribution, of course, also 

The addition of electrons to molecules changes their shape e.g. NOj (trigonal planar) to NOj (V-shaped) SO3 (trigonal planar) to (tetrahedral). The 

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