Enzyme inhibitors

• What is enzyme inhibition?


  Slowing down or stopping enzyme action
• What are substances that inhibit enzyme reactions called?

  Inhibitors
• What are the two types of enzyme inhibitors?

  Competitive and non-competitive inhibitors
• How do competitive inhibitors function?

  • Similar shape to substrate
  • Bind to active site
  • Block formation of enzyme-substrate complexes
  • Rate of reaction is reduced
  • Increased substrate concentration can overcome inhibition
• What happens when a competitive inhibitor binds to the active site?

  The rate of reaction is reduced
• How does malonate affect succinate dehydrogenase?

  It competes with succinate for the active site
• How do non-competitive inhibitors function?

  • Do not resemble substrate
  • Bind to allosteric site
  • Change shape of active site
  • Prevent substrate binding
  • Permanent inhibition, not affected by substrate concentration
• Where do non-competitive inhibitors bind on the enzyme?

  Allosteric site
• What effect does a non-competitive inhibitor have on the enzyme's active site?

  It modifies the shape, preventing substrate binding
• Can increasing substrate concentration reduce the effects of a non-competitive inhibitor?

  No, it cannot reduce the effects
• What are the key differences between competitive and non-competitive inhibition?

  • Competitive inhibitors:
  • Similar shape to substrate
  • Bind to active site
  • Temporary inhibition
  • Can be overcome by increasing substrate concentration

  
  

  • Non-competitive inhibitors:
  • Do not resemble substrate
  • Bind to allosteric site
  • Permanent inhibition
  • Cannot be overcome by increasing substrate concentration