B2- Enzymes

• What are enzymes essential for in living organisms?

  They make chemical reactions work.
• What role do enzymes play in chemical reactions?

  • Enzymes are biological catalysts.
  • They speed up useful chemical reactions.
  • They reduce the need for high temperatures.
• What is a catalyst?

  A substance that increases reaction speed.
• What are enzymes made of?

  Enzymes are all proteins.
• Why do enzymes have unique shapes?

  To perform their specific catalytic functions.
• What is the active site of an enzyme?

  The region where substrates bind for reactions.
• How does the 'lock and key' model describe enzyme action?

  It shows how substrates fit into active sites.
• What happens to an enzyme when it is denatured?

  Its active site shape changes, preventing reactions.
• What factors affect the rate of enzyme-catalyzed reactions?

  Temperature and pH levels.
• What is the effect of high temperatures on enzymes?

  They can break bonds and denature the enzyme.
• What is the optimum temperature for enzymes?

  The temperature at which they work best.
• How does pH affect enzyme activity?

  Extreme pH levels can denature enzymes.
• What is the optimum pH for most enzymes?

  Often neutral pH 7.
• What is unique about pepsin's optimum pH?

  It works best at pH 2 in the stomach.