RP 5 - Enzymes

• What is the first step in investigating the effect of pH on the rate of reaction of the amylase enzyme?

  Place starch solution, amylase solution, and buffer solution in a water bath at 25°C for a few minutes
• Why is it important to place the solutions in a water bath before mixing?

  To allow temperature to equilibrate
• How would you test the reaction mixture for the presence of starch?

  Add a drop of the mixture to iodine solution on a tile
• What is the procedure for determining when the reaction has completed in the investigation?

  Add the mixture to iodine solution drops on the tile at fixed 30s intervals until the iodine solution remains brown
• How do you calculate the rate of reaction in this investigation?

  Calculate the rate of reaction using \( \frac{1}{\text{time taken for solution to remain brown}} \)
• What should you do after calculating the rate of reaction at different pH values?

  Plot a graph of rate (y) against pH (x)
• Which enzyme catalyses the breakdown of starch in the human digestive system?

  Amylase
• What does amylase catalyse the breakdown of starch into?

  Maltose
• What is a buffer solution?

  A solution which can resist changes in pH