The diagram below shows the rate of an enzyme controled reaction. The solid line indicates the normal relationship between rate and substrate concentration and the dotted line indicates the relationship when a competitive inhibitor is added.  


a.i)   Explain how a competitive inhibitor acts  
  ii)  Explain why in the graph above the inhibitor is a competitive inhibitor?  
 The graph below shows the relationship between rate of reaction and temperature of most enzyme reaction.  


b.    Explain why the relationship is that shown on the graph.