investigating enzymatic reactions

• What enzyme catalyses the breakdown of starch?

  Amylase
• How can you detect starch in a solution?

  Using iodine solution
• What is the first step in investigating pH's effect on amylase activity?

  Put iodine solution in a spotting tile
• What temperature should the water be heated to for the experiment?

  35 °C
• What should be used to measure the temperature of the water?

  A thermometer
• Why is it important to keep the temperature constant during the experiment?

  To ensure a fair test
• What volumes of amylase and buffer solution are added to the boiling tube?

  1 cm³ each
• What is the pH of the buffer solution used in the experiment?

  6
• What should be done immediately after adding starch solution to the boiling tube?

  Mix the contents and start a stop clock
• How often should samples be taken from the boiling tube?

  Every 10 seconds
• What indicates that starch is no longer present in the solution?

  The iodine solution remains brown-orange
• Why is it important to control variables in the experiment?

  To make it a fair test
• What is the formula to calculate the rate of reaction?

  • Rate = $\frac{1000}{time}$
• If the time taken for amylase to break down starch is 90 seconds, what is the rate of reaction?

  11.1
• How is the rate of reaction calculated in general?

  Change divided by time taken
• If 24 cm³ of oxygen is released in 50 seconds, what is the rate of reaction?

  0.48 cm³/s
• What other factors can be investigated to affect amylase activity?

  • Temperature
  • Enzyme concentration
  • Substrate concentration
• What is another way of writing cm³/s?

  cm³s
• What is the significance of measuring the amount of product formed in an enzyme-controlled reaction?

  It indicates the reaction's progress