Question

what is the relative activity and the degree of inhibition caused by a competitive inhibitor when [S]=km and [I]= ki?

please show the work

Answer 1

  Relative reactivity:

it determines whether an element can replace another element in a single replacement reaction.

K_i' is much greater than the total inhibitor concentration and the ESI complex is not formed.

This occurs when both the substrate and inhibitor compete for binding to the active site of the enzyme.

The inhibition is most noticeable at low substrate concentrations but can be overcome at sufficiently high substrate concentrations as the V_max remains unaffected The rate equation is given by:

  

where K_m^app is the apparent K_m for the reaction, and is given by:

  

Normally the competitive inhibitor bears some structural similarity to the substrate, and often is a reaction product (product inhibition, e.g. inhibition of lactase by galactose),

which may cause a substantial loss of productivity when high degrees of conversion are required.

The rate equation for product inhibition is derived from equations .

  

A similar effect is observed with competing substrates.