CP 2: pH & Enzyme Activity

• What is the aim of the experiment on the effect of pH on amylase activity?

  To determine the time taken for starch to be completely digested at different pH values
• What equipment is needed for the experiment on amylase activity?

  • Test tubes
  • Test tube rack
  • Water baths
  • Spotting tiles
  • Measuring cylinder
  • Syringes
  • Glass rod
  • Stopwatch
  • Starch solution
  • Amylase solution
  • Buffered solutions
  • Iodine solution
  • Thermometer
• What is the first step in the method of the experiment?

  Label each well on a tile with the time and add a drop of iodine solution
• How much buffer solution should be added to each test tube?

  2 cm​3​
• What pH range should the buffer solutions cover in the experiment?

  From pH 3.0 to 7.0
• Why is it important to allow the temperature to equilibrate before starting the experiment?

  To ensure consistent temperature for enzyme activity
• What should be done immediately after adding starch to the test tube with amylase?

  Start timing immediately
• How often should the mixture be tested with iodine solution?

  Every 30 seconds
• What indicates that all the starch has been digested in the experiment?

  The iodine solution remains brown and does not turn blue-black
• How many times should steps 1-8 be repeated to obtain a mean time?

  Twice more
• How is the rate of enzyme reaction calculated?

  By using \( \frac{1}{\text{time taken for iodine solution to remain brown}} \)
• What should be done after calculating the rate of enzyme reaction for different pH values?

  Plot a graph of the rate of enzyme reaction against pH
• What are the controlled variables in the amylase activity experiment?

  • Temperature
  • Volume and concentration of starch solution
  • Volume and concentration of amylase solution
  • Time interval between testing
• What is a potential source of error in the experiment?

  The time interval between testing each sample may be too long
• What safety precautions should be taken during the experiment?

  Avoid contact with iodine solution and be careful with hot water
• What should be done if using a Bunsen burner during the experiment?

  Tie long hair back and wear goggles
• What is the time taken for amylase to completely break down all the starch measured in?

  In seconds (s)
• What is the relationship between pH and the rate of amylase activity?

  • The rate of enzyme activity varies with different pH levels.
  • Optimal pH can enhance enzyme activity.
  • Extreme pH levels can denature the enzyme.
• What is the function of amylase?

  It breaks carbohydrate (starch) into smaller sugars.

  
• Where is amylase primarily active in the human body?

  In the mouth and small intestine.
• What type of molecule is starch?

  Starch is a carbohydrate.
• What is the product of starch breakdown by amylase?

  Maltose, a sugar molecule.
• What solution is used to test for the presence of starch?

  Iodine solution is used to test for starch.
• What are the main components involved in the action of amylase?

  • Amylase enzyme
  • Carbohydrate (starch)
  • Sugar molecules (maltose)