Download Catalase Lab

Catalase Lab
Introduction: Catalase is an enzyme normally found in many plant and animal tissues. Its purpose is to destroy
toxic substances which may be introduced into cells. Also, some cells use catalase to destroy cellular debris or worn
out organelles. In this lab, we will use a catalase solution from potatoes and determine the effect of temperature and
pH on the action of this enzyme. The substrate of the enzyme will be 3% hydrogen peroxide (H2O2). Catalase
works by the following mechanism:
2 H2O2 ------------------>____2 H2O+ O2
Materials:
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1M HCl
6 test tubes
hot water bath
graduated cylinder
1M
NaOH
test tube rack
ice bath
100 ml beaker
H2O2
test tube holder
Safety: HCl and NaOH are strong acids and bases. If you spill these chemicals on your skin, immediately wash in
running water. Wear goggles at all times. Be careful of hot water and hot plates.
Procedure:
Part A:
1. Label 3 test tubes hot, cold and room temp.
2. Place 3ml of potato catalase into each test tube.
3. Place the test tube labeled hot in the hot water bath for 3 minutes.
4. Place the test tube labeled cold in the cold water bath for 3 minutes and the test tube labeled room temperature
leave in the test tube rack.
5. After 3 minutes, add 3ml of H2O2 to each tube.
6. Wait one minute and record the height of the bubbles in each tube in cm. Record in Table 1. Measure the radius
of the test tube and record in Table 1.
Part B:
1. Label 3 test tubes acid, base and water.
2. Place 3ml of potato catalase into each test tube.
3. Add 10 drops of HCl to the tube labeled acid, 10 drops of NaOH to the tube labeled base and 10 drops of water
to the tube labeled water. Mix contents by gently swirling.
4. Wait 2 minutes then add 3ml of H2O2 to each tube.
5. Wait 1 minute for reaction to occur, then measure the height of the bubbles in cm. Record in Table 2.
6. Measure the radius of the test tube and record in Table 2.
Part C:
1. Calculate the volume of each reaction using the equation πr2h. Record results in data table.
Data:
Table 1: Effect of Temperature on Catalase Reactions
Height of Bubbles
(cm)
Radius of Test Tube
(cm)
Volume of Reaction
(cm3)
Hot
Room Temp
Cold
Table 2: Effect of pH on Catalase Reactions
Height of Bubbles
(cm)
Radius of Test Tube
(cm)
Volume of Reaction
(cm3)
Acid
Neutral
Base
Analysis:
1. What effect did heat have on the activity of the enzyme? What effect did cold have? Room Temperature?
2. What type of biological molecule are enzymes?
3. Describe how an enzyme works and its importance to all living organisms.
4. What effect did lowering the pH have on the activity of the enzyme? Raising the pH?
5. What were the controls in this experiment?