enzymes

• enzymes are biological catalysts (speed up reactions)
• enzymes can break up large molecules and join small molecules
• lock and key hypothesis :

  shape of substrate is complementary to the shape of the active site

  
• denature = to change the shape of a protein so that it cannot carry out its normal function
• What is the purpose of the core practical described in the study material?

  To find the optimum pH at which the enzyme activity is greatest
• What equipment is set up for the experiment?

  Bunsen burner, heatproof mat, tripod, and gauze
• At what temperature should the water be maintained during the experiment?

  About 35°C
• How many drops of iodine solution are added to each spot of the spotting tile?

  Two drops
• What is added to the test tube along with the amylase enzyme solution?

  2 cm³ of starch solution
• What is the purpose of adding 1 cm³ of pH solution to the test tube?

  To keep the pH constant
• What should be done after mixing the solution in the test tube?

  Place it into the beaker of water on the Bunsen burner
• How often should drops of solution be removed from the test tube for testing?

  Every 20 seconds
• What indicates that the reaction has stopped during the experiment?

  The iodine solution stops turning black
• What should be recorded at the end of the experiment?

  The time it takes for the iodine solution to stop turning black
• What should be done after completing the experiment with one pH solution?

  Repeat with different pH solutions
• what is the rate calculation for enzyme activity ?

  Rate = change / time
• • Carbohydrases convert carbohydrates into simple sugars e.g amylase breaking down starch into maltose
  • produced in salivary glands, pancreas and small intestine (most of starch digested here)
• • lipases convert lipids (fats) unto fatty acids and glycerol
  • produced in pancreas and small intestine
• • proteases convert proteins into amino acids
  • e.g. pepsin produced in stomach, other forms found in pancreas and small intestine