Overview

• What are enzymes classified as?

  Biological catalysts
• How do enzymes affect chemical reactions?

  They speed up reactions without being consumed
• Why are enzymes crucial for life?

  They regulate biochemical reactions in organisms
• What are enzymes made of?

  Proteins
• What is the active site of an enzyme?

  A region that binds to substrates
• What is the primary structure of an enzyme?

  The sequence of amino acids
• What does the tertiary structure of an enzyme refer to?

  The overall three-dimensional shape
• What is the quaternary structure of some enzymes?

  Multiple polypeptide chains working together
• What is the enzyme-substrate complex?

  Binding of substrate to the enzyme's active site
• What does the lock-and-key model describe?

  Enzyme's active site fits substrate perfectly
• What is the induced fit model?

  Enzyme's active site adjusts to fit substrate
• How do enzymes lower activation energy?

  By stabilizing the transition state
• What is the role of proximity and orientation in enzyme action?

  Increases likelihood of successful collisions
• How do enzymes create a microenvironment for reactions?

  By providing an acidic or basic environment
• How do enzymes strain substrate bonds?

  By inducing strain on specific bonds
• What is the optimal temperature for most human enzymes?

  Around 37°C
• What happens to enzymes at high temperatures?

  They denature and lose activity
• What is the optimal pH for pepsin?

  Around 2
• How does substrate concentration affect enzyme activity?

  Increases until saturation occurs
• What is saturation in enzyme activity?

  All active sites are occupied by substrate
• How does increasing enzyme concentration affect reaction rate?

  Increases rate with constant substrate concentration
• What are competitive inhibitors?

  Molecules that compete for the active site
• How can competitive inhibition be overcome?

  By increasing substrate concentration
• What are non-competitive inhibitors?

  Molecules that bind to allosteric sites
• What is the effect of non-competitive inhibitors on enzyme activity?

  Cannot be reversed by adding more substrate
• What is the Michaelis-Menten model?

  Describes the relationship between reaction rate and substrate concentration
• What does Vmax represent in enzyme kinetics?

  The maximum rate of reaction
• What does Km indicate in enzyme kinetics?

  The substrate concentration at half of Vmax
• What is the Lineweaver-Burk plot used for?

  To determine Km and Vmax from data
• What is allosteric regulation?

  Regulation by molecules binding to allosteric sites
• What is feedback inhibition?

  End product inhibits an earlier enzyme
• How can enzymes be modified covalently?

  By adding or removing phosphate groups
• How is enzyme synthesis regulated?

  At the level of gene expression
• What are cofactors?

  Additional molecules required for enzyme function
• What are coenzymes?

  Organic molecules often derived from vitamins
• What is the role of cofactors and coenzymes in enzyme activity?

  Assist in substrate binding and enzyme function
• What are the mechanisms of enzyme action?

  1. Lowering Activation Energy
  2. Proximity and Orientation
  3. Microenvironment
  4. Straining Substrate Bonds
• What factors affect enzyme activity?

  1. Temperature
  2. pH
  3. Substrate Concentration
  4. Enzyme Concentration
  5. Inhibitors
  6. Cofactors and Coenzymes
• What are the applications of enzymes?

  1. Metabolism
  2. Industrial Applications
  3. Medical Uses
• What are the levels of enzyme structure?

  1. Primary Structure
  2. Secondary Structure
  3. Tertiary Structure
  4. Quaternary Structure