1.9 - Enzyme Inhibition

• What are enzyme inhibitors ?


  Substances that interfere with the functioning of the active site of an enzyme so reduce its activity
• What are the 2 types of inhibitor ?


  Competitive and non-competitive
• Where does a competitive inhibitor bind to ?


  The active site of the enzyme
• Where does a non-competitive inhibitor bind to ?

  Binds to another binding site on the enzyme that’s not the active site
• What shape do competitive inhibitors have ?


  Similar shape to the substrate
• What do competitive inhibitors compete with ?


  The substrate for available active sites
• How to reduce the effect of a competitive inhibitor ?


  Increasing the concentration of the substrate so less inhibitor binds
• What do inhibitors prevent the formation of ?


  Enzyme-substrate complex
• Do competitive inhibitors permanently bind to the active substrate ?


  No
• How does a non-competitive prevent an ESC from forming ?


  It changes the shape of the active site so it’s no longer complementary to the substrate so an ESC can’t form
• What effect does increasing substrate conc have on the effects of a non-competitive inhibitor ? 


  No effect as it doesn’t bind to the active site
• How does the non-competitive inhibitor change the active site shape ?

  It disrupts the bonding therefore changing the enzymes tertiary structure
• What shape graph occurs when the substrate concentration continues to increase and it’s against the rate of reaction ? And why ?


  No available active sites left to fill so rate stays constant