enzyme inhibitors

• What is an enzyme inhibitor?

  Any substance that decreases enzyme activity
• What are the two types of enzyme inhibitors?

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

  They fit into the active site instead of substrate
• What is a key characteristic of competitive inhibitors?

  They are structurally similar to the substrate
• Why should you not say competitive inhibitors are the same shape as substrates?


  They have a similar shape, not identical
• What happens when a competitive inhibitor collides with an enzyme?

  It may prevent enzyme-substrate complex formation
• How does increasing substrate concentration affect competitive inhibition?

  It decreases the effect of the inhibitor
• What do non-competitive inhibitors bind to?

  Any part of the enzyme except the active site
• What is the effect of non-competitive inhibitors on enzyme shape?

  They alter the overall shape of the enzyme
• How does increasing substrate concentration affect non-competitive inhibition?

  It does not increase the rate of reaction
• How can you identify competitive and non-competitive inhibition on a graph?

  • Curve A: Competitive inhibition (increased substrate reduces effect)
  • Curve B: Non-competitive inhibition (substrate concentration has no effect)
• What does the x-axis represent in the inhibition graph?

  Increasing substrate concentration
• What does curve A on the graph indicate?

  It represents competitive inhibition
• What does curve B on the graph indicate?

  It represents non-competitive inhibition
• Why can only competitive inhibition be reduced by increasing substrate concentration?


  Because it competes for the active site
• What is the relationship between enzyme-substrate complexes and inhibitors?

  Inhibitors prevent successful enzyme-substrate complexes
• look at this graph

  line A: competitive

  line B: non-competitive