Enzyme inhibitors

• What are enzyme inhibitors?

  Substances that reduce enzyme reaction rates
• How do inhibitors affect metabolic activity?

  They can significantly reduce metabolic activity
• What is an example of an inhibitor?

  Many drugs and poisons
• Why is inhibition vital in nature?

  It allows control over biological process rates
• What is end product inhibition?

  Control of a metabolic pathway by an inhibitor
• How does high ATP concentration affect respiration?


  It inhibits an enzyme at the pathway's start
• What happens to the active site when ATP binds to an allosteric site?

  It changes shape, preventing substrate binding
• What occurs when ATP concentration decreases?

  The pathway resumes due to enzyme activation
• What does "allosteric" mean?


  "Other site" on the enzyme
• How do competitive inhibitors function?

  They compete with substrates for the active site
• What happens to the inhibiting effect of competitive inhibitors as substrate concentration rises?


  The effect diminishes as substrate concentration increases
• What are protease inhibitors used for?

  To treat HIV infection
• How do non-competitive inhibitors affect enzyme activity?

  They change the active site's shape
• Does the inhibiting effect of non-competitive inhibitors diminish with increased substrate concentration?

  No, it does not diminish
• What is the role of coenzymes?


  Transporters of chemical groups between reactants
• How do coenzymes interact with substrates?

  They bind temporarily to the active site
• What happens to coenzymes during reactions?

  They are changed and recycled
• What is an example of a coenzyme derived from a vitamin?

  NAD from vitamin B3
• What is a prosthetic group?

  A permanent part of an enzyme
• How do prosthetic groups contribute to enzymes?

  They affect the enzyme's shape and properties
• What is an example of a prosthetic group?

  The haem group in catalase
• What are inorganic ion cofactors?


  Non-protein components required for enzyme activity
• How do inorganic ions assist enzyme reactions?

  They help form enzyme-substrate complexes
• Why are enzymes produced in inactive forms?

  To prevent damage to body tissues
• What is a holoenzyme?


  The activated form of an enzyme
• What are the types of enzyme inhibitors?

  • Competitive inhibitors
  • Non-competitive inhibitors
  • Allosteric inhibitors
  • End product inhibitors
• What are the roles of coenzymes and prosthetic groups?

  • Coenzymes: Transport chemical groups, recycled
  • Prosthetic groups: Permanent enzyme components, affect shape