Lysozyme and the induced fit model

• what is the induced fit model?

  the change in shape of the active site of an enzyme, induced by the entry of the substrate, so that the enzyme and substrate bind closely
• whats an example of an enzyme molecule that fits the lock-and-key model better and why?

  tyrosine kinase as it seems to be more rigid than others
• why are some enzyme molecules a better fit for the induced fit model?

  as they are more flexible
• whats an example of a flexible enzyme molecule that fits the induced fit model better?

  lysozyme
• what is lysozyme?


  an anti-bacterial enzyme
• where can lysozyme be found?

  in human saliva, mucus and tears
• how can lysozyme be explained through the induced fit model?

  • its active site is a groove, and sugars on the bacterial cell wall fits into it
  • the groove closes over the sugars and the lysozyme molecule changes shape around the sugars and hydrolyses the bonds holding them together
  • the cell wall is weakened; the bacteria absorb water by osmosis and burst
• what happens when the groove of the active site of lysozyme (groove) closes over the chain of sugars on the bacteria?

  this strains the bonds holding the sugars together and lowers the activation energy needed to break them
• what is this a diagram of?

  the induced fit model