1.5 Enzymes

• Enzymes are biological catalysts that speed up chemical reactions in living organisms.
• The active site of an enzyme is the region where the substrate binds and the reaction occurs.
• What is the key concept of the lock and key model?

  Complementary shapes of enzyme and substrate
• The lock and key model ensures that enzymes interact with only specific substrates.


  True
• How does the induced fit model differ from the lock and key model?

  Active site is flexible
• What does the term 'specificity' refer to in the context of enzymes?

  Binding to specific substrates
• Enzymes lower the activation energy required for a chemical reaction to occur.


  True
• An enzyme-substrate complex forms when the substrate binds to the active site.
• The active site of an enzyme in the lock and key model has a fixed, complementary shape to the substrate.
• Match the enzyme model with its description:

  Lock and Key ↔️ Fixed, complementary active site

  Induced Fit ↔️ Active site changes shape
• In the induced fit model, the active site is described as flexible, adapting to the substrate’s shape.
• The induced fit model proposes that the active site changes shape to better accommodate the substrate.
• Enzymes lower the activation energy by stabilizing the transition state of the reaction
• The lock and key model suggests the active site has a rigid, pre-formed shape


  True
• What is the optimal temperature for human enzymes to function?

  37°C
• What are enzymes defined as in biological terms?

  Biological catalysts
• The lock and key model explains enzyme specificity based on complementary shapes


  True
• Match the enzyme model with its feature:

  Lock and Key ↔️ Fixed active site shape

  Induced Fit ↔️ Flexible active site
• Human enzymes function best at a pH of 7


  True
• What is the role of enzymes in reducing activation energy within metabolic pathways?

  Speeds up reactions
• What is the primary idea behind the induced fit model?

  Active site changes shape
• The induced fit model explains how enzymes stabilize the reaction transition state.


  True
• What type of active site does the lock and key model propose?

  Fixed, complementary shape
• What does the induced fit model propose about the active site of an enzyme?

  It is flexible
• The flexibility of the active site in the induced fit model allows enzymes to lower the activation energy
• Substrate concentration continues to increase enzyme activity indefinitely

  False
• Enzymes lower the activation energy required for a chemical reaction
• What does the lock and key model propose about the active site of an enzyme?

  It is complementary to the substrate
• Why is the induced fit model considered more efficient than the lock and key model?

  Optimizes substrate binding
• Enzymes catalyze chemical reactions within metabolic pathways