What are Enzymes

• What are enzymes?

  Enzymes are large proteins that catalyze chemical reactions
• Why are enzymes important for living cells?

  Enzymes speed up chemical reactions that are naturally slow
• What is the definition of a catalyst?

  A substance that increases the speed of a chemical reaction without being changed or used up
• What is the difference between a catalyst and an enzyme?

  Enzymes are a type of catalyst made by living organisms
• How do enzymes work to speed up chemical reactions?

  Enzymes have an active site that is complementary to substrates
• What is the lock and key model of enzyme action?

  The substrate fits perfectly into the active site of the enzyme
• How does the induced fit model differ from the lock and key model?

  The enzyme changes shape slightly to better fit the substrate
• If the substrate does not fit the active site of an enzyme, what will happen?

  The reaction will not be catalyzed by the enzyme
• What are the strengths and weaknesses of the lock and key model and the induced fit model of enzyme action?

  Strengths:

  • Lock and key model: Explains enzyme specificity
  • Induced fit model: Explains how enzymes can bind substrates that don't perfectly fit

  
  

  Weaknesses:

  • Lock and key model: Does not explain how enzymes can bind substrates that don't perfectly fit
  • Induced fit model: More complex to understand
• What is the key reason enzymes are so important for living cells?

  Enzymes speed up chemical reactions that are naturally slow
• What is the main difference between a catalyst and an enzyme?

  Enzymes are a type of catalyst made by living organisms
• Why do enzymes have an active site that is complementary to substrates?

  To allow the enzyme to catalyze a specific chemical reaction
• What is the key difference between the lock and key model and the induced fit model of enzyme action?

  The induced fit model says the enzyme changes shape to fit the substrate
• If a substrate does not fit the active site of an enzyme, what will happen to the reaction?

  The reaction will not be catalyzed by the enzyme