Enzyme Lab. How does altering pH affect the reaction rate of catalase on hydrogen peroxide?

Temperature

The concentration of the hydrogen peroxide (the volume of hydrogen peroxide in the beaker)

Materials:

• 12 g pig liver
• 600 mL 3% Hydrogen peroxide solution
• 6 100 mL beakers
• 1 L Hydrogen chloride solution (1 mol/L)
• 1 L Sodium hydroxide solution (1 mol/L)
• pipette
• Tweezers
• Thermometer
• Scalpel
• pH probe
• LabQuest
• Timer
• Electronic balance
• Gloves (optional)

Procedure:

1. Using the scalpel and tweezers cut 6 pieces of liver, each having a mass of 2 g
2. Place 6 100 mL beakers adjacent to each other; fill each beaker with 50 mL of hydrogen peroxide solution
3. Label the beakers controlled, pH 3, pH 5, pH 7, pH9 and pH 11
4. Using the pH probe, measure the pH of the beaker labeled Controlled and record the value in the data table below
5. Adjust the pH levels of the rest of the beakers by adding drops of either HCl or NaOH to the beakers using the pipette. HCl should be added to decrease the pH, NaOH should be added to increase the pH. Using the pH probe, gently stir the solution to assure that it is well mixed.
6. Using a thermometer, measure the temperature of each solution to assure that the temperature is constant.
7. Place the 2 g liver into the beaker marked controlled. Start the timer when bubbles start to appear. Stop the timer as the solution stops bubbling. Record the time in the observation chart below.
8. Repeat step 7 for the other 5 beakers.
9. Graph the observations onto the graph below.

The Rate of Reaction of Catalase under Various pH levels