Enzymes and digestion

• What are enzymes?

  Biological molecules that act as catalyst
• What are enzymes made from?


  Protein
• What substrate is broken down by carbohydrase?

  Carbohydrates
• What substrate is broken down by lipase?

  Lipids/fats
• What substrate is broken by protease?


  Protein
• What substrate is broken down by amylase?


  Starch
• Explain the lock and key theory

  An enzyme has an active site that is complementary and shape. The enzyme breaks the substrate down into its products. The enzyme is not used up.
• What is meant by substrate specificity?

  Each enzyme will only work on one substrate
• What factors affect enzyme activity?

  Temperature, pH, and enzyme concentration
• Explain why increasing temperature from 10° to 30° increases enzyme activity

  Increasing the temperature increases kinetic energy, the number of collisions and the amount of product formed
• What is meant by optimum temperature?

  The temperature that causes the maximum rate of activity
• Explain why the rate of reaction decreases temperature greater than the optimum

  The activity site changes shape so is no longer complementary to the shape of the substrate
• What inhibitor and how does it affect enzyme activity?

  Molecules that fit loosely or partially into the active site and prevent substrate molecules from entering. The rate of reaction is reduced.
• What is digestion?

  The breakdown of large, insoluble molecules into small soluble ones that can be absorbed
• what is absorption?

  The products of digestion pass through into the blood
• Enzymes are used in washing powder and thermostable. What does this mean?


  Enzymes can work on a wide range of temperatures
• What does the economic benefits of this?

  Less money is needed to heat the water to lower temperature
• Function of ileum?

  Where absorption of digestion nutrients take place
• How is ileum adopted for its function?

  Large surface area, good blood supply, thin,Permeable
• How is villus adopted for absorption?


  Finger like shape, single layer cells, capillar network, lacteal