Enzymes

• What type of proteins are enzymes?

  Tertiary structure proteins
• What is the function of enzymes?

  To catalyze different reactions
• What part of an enzyme is involved in catalyzing reactions?

  The active site
• What is the role of the active site in enzyme action?

  It binds to the substrate
• What forms when the active site binds to the substrate?

  Enzyme-substrate complexes
• How is the shape of the active site determined?

  By the tertiary structure of the protein
• Why is the unique 3D shape of an enzyme important?

  It creates a specific active site for substrates
• What is the term that is key in enzyme-related questions?

  Enzyme-substrate complex
• What do enzymes lower to catalyze reactions?

  The activation energy
• What are enzymes used for (Ea)

  Enzymes lower the activation energy needed
• How does the lock and key model describe enzyme action?

  The enzyme's active site is a fixed shape
• What are the two models of enzyme action mentioned?

  Lock and key, induced fit
• What happens to the substrate in the lock and key model?

  It distorts slightly to lower activation energy
• How does the induced fit model differ from the lock and key model?

  The active site changes shape to fit the substrate
• What does the induced fit model suggest about the enzyme's active site?

  It molds around the substrate upon binding
• What effect does the induced fit model have on substrate bonds?

  It puts strain on the bonds, weakening them
• What happens to the active site after the reaction in the induced fit model?

  It returns to its original shape
• What is the accepted model for how enzymes function?

  The active site changes shape to mold around the substrate
• What are the key features of enzyme action?

  • Enzymes are tertiary structure proteins
  • They catalyze reactions by lowering activation energy
  • Active site binds to complementary substrate
  • Enzyme-substrate complexes form during reactions
  • Two models: lock and key, induced fit