Enzymes

• What is an enzyme?

  An enzyme is a protein that acts as a biological catalyst that speeds up a reaction, not change it.
• What is the Lock and Key Theory?

  1. The active site is a specific shape.
  2. This is complementary to the substrate.
  3. The reaction will only catalyse is the substrate fits the active site and if they are complementary.
  4. At the active site, enzymes break down large, insoluble molecules into smaller, soluble molecules that can be absorbed.
  5. When the products have been released, the enzyme's active site can accept another substrate molecule.
• The effect of temperature on enzymes:

  • As the temperature increases,
  • The rate of reaction increases,
  • Because enzyme and substrate molecules move around faster and collide more frequently.
• What is optimum temperature?

  When the reaction works as fast as possible.
• What happens to an enzyme in extreme pHs or temperatures?

  -The shape of the active site changes.

  -This means that the substrate can no longer bind to the active site, so the enzyme can't catalyse the reaction.
• What is it called when an enzyme can no longer function?

  Denaturation.
• The effect of pH on enzymes:

  • Different enzymes have different optimum pH values.
  • This allows enzymes to be adapted to function well in environments with different pH's.
• What is the best pH for amylase? 


  7- neutral
• What is the best pH for protease?

  2- acidic
• What enzyme breaks down carbohydrates?

  Amylase
• What enzyme breaks down protein?

  Protease
• What enzyme breaks lipids?

  Lipase
• What is carbohydrates broken down into?

  Glucose
• What is protein broken down into?

  Amino Acids
• What are lipids broken down into?

  Fatty Acids

  Glycerol
• Where are amylase found?

  • Salivary Glands
  • Pancreas
  • Small Intestine
• Where are protease found?

  • Stomach
  • Pancreas
  • Small Intestine
• Where are lipase found?

  • Small Intestine
  • Pancreas