Lab Report Using a Chemical Titration to Measure Rate of Conversion of Hydrogen Peroxide to Water and Oxygen
In this laboratory you will use a chemical titration to measure and then calculate the rate of conversion of hydrogen peroxide (HO) to water and oxygen using the enzyme catalase.
Before doing this exercise, you should understand:
Ø the general functions and activities of enzymes
Ø the relationship between the structure and function of enzymes
Ø the concept of initial reaction rates of enzymes
Ø how the concept of free energy relates to enzyme activity
Ø that changes in temperature, pH, enzyme concentration, and substrate concentration can affect the initial reaction rates of enzyme-catalyzed reactions.
After doing the exercise, you should be able to:
ü measure the effects of changes of temperature, pH, enzyme concentration, and substrate concentration on rates of an enzyme-catalyzed reaction in a controlled experiment.
ü explain how environmental factors affect the rate of enzyme-catalyzed reactions.
· 5mL and 10mL syringe
· 1mL pipet
· 60mL plastic cup
· hot plate
· test tubes
· test tube tongs
· marker (to label)
· potassium promgemte
· sulfuric acid
· hydrogen peroxide
· bovine liver
· distilled water
Part A: Test of Catalase Activity
1. a) Transfer 10 mL of 1.5% (0.44 M) hydrogen peroxide
(H2O2) into a 50-mL glass beaker.
b) Add 1 mL of freshly made catalase solution.
2. a) Fill a glass beaker with 300 mL of water.
b) Place beaker on a burner and allow it to boil.
c) Transfer 5 mL of purified catalase extract to a test tube.
d) Put the test tube with the catalase extract in the beaker on
the burner and leave it for 5 minutes.
e) Allow the catalase to cool.
f) Transfer 10 mL of 1.5% hydrogen peroxide (H2O2)
into a 50-mL glass beaker.
g) Add 1 mL of the cooled, boiled catalase solution.
Part B: The Establishment of a Baseline
*These procedures must be performed without adding catalase
(enzyme) to the reaction mixture.
1. Accumulate 10 mL of 1.5% hydrogen peroxide (H2O2), two
50-mL glass beakers, 10 ml of 1M sulfuric acid (H2SO4),
approximately 6 mL of 2% potassium permanganate (KMnO4)
1 mL of water (H2O), two appropriately labeled syringes
(for contamination prevention), white paper, a pipette, aprons,
goggles, and gloves.
2. Put on aprons, protective goggles, and latex gloves.
3. a) Put 10 mL of 1.5% hydrogen peroxide (H2O2) into a clean
b) Add 1 mL of water (H2O), in place of the enzyme solution.
c) Add 10 mL of 1M sulfuric acid (H2SO4),
USING EXTREME CAUTION WHEN HANDLING
d) Mix well via a pipette.
4. Using a...