enzyme inhibitors

• What are enzyme inhibitors?

  Substances that reduce enzyme activity
• What are the two types of enzyme inhibitors?

  Competitive and non-competitive inhibitors
• Where do competitive inhibitors bind on an enzyme?

  To the active site
• Where do non-competitive inhibitors bind on an enzyme?

  To the allosteric site
• What is the shape similarity of competitive inhibitors to substrates?

  They have a similar shape
• What happens when competitive inhibitors bind to the active site?

  No reaction takes place
• What is the effect of competitive inhibitors on enzyme-substrate complexes?

  Fewer enzyme-substrate complexes form
• How does sulphanilamide prevent bacteria from producing folic acid?

  It acts as a competitive inhibitor
• What is the effect of adding a competitive inhibitor on the maximum rate of reaction?

  It does not affect the maximum rate
• How can the effects of a competitive inhibitor be reduced?

  By adding more substrate
• What happens when non-competitive inhibitors bind to the allosteric site?

  The tertiary structure of the active site changes
• What is the effect of non-competitive inhibitors on enzyme-substrate complexes?

  Fewer or no enzyme-substrate complexes form
• What is the effect of adding a non-competitive inhibitor on the maximum rate of reaction?

  It reduces the maximum rate
• Can the effects of a non-competitive inhibitor be reduced by adding more substrate?

  No, they cannot be reduced
• What is the allosteric site on an enzyme?

  A site where non-substrate molecules bind
• How do some substances act as enzyme activators?

  By binding to the allosteric site
• What effect do enzyme activators have on the active site?

  They change its tertiary structure
• What is the result of enzyme activators binding to the allosteric site?

  More enzyme-substrate complexes form
• What is the overall effect of enzyme activators on the rate of reaction?

  It increases the rate of reaction
• What are the actions of competitive inhibitors?

  • Bind to the active site
  • Have a similar shape to substrates
  • Reduce the rate of reaction without affecting maximum rate
• What are the actions of non-competitive inhibitors?

  • Bind to the allosteric site
  • Change the tertiary structure of the active site
  • Reduce both the rate of reaction and maximum rate
• How do enzyme activators function?

  • Bind to the allosteric site
  • Change the tertiary structure of the active site
  • Increase the rate of reaction by forming more enzyme-substrate complexes