1. Do Now (on loose-leaf) What is catalase?
What does catalase break down?
What is the chemical formula that shows this process? (Reactants  Products)
An enzyme
Hydrogen peroxide (H2O2)
2H2O2 ----> 2H2O + O2 (fix)
Review Lab Procedures silently and independently

2. How Enzymes Work
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3. How Enzymes Work Enzymes are proteins
Lower the activation energy of a chemical reaction

4. Enzyme-Substrate Complex
The substance (reactant) an enzyme acts on is the substrate
Enzyme
Joins
Substrate

5. Active Site
A restricted region of an enzyme molecule binds to the substrate
Binding occurs at the active site
LOCK AND KEY
Active Site
Enzyme
Substrate

7. Enzyme-substrate complex

8. Catalase Enzyme Lab
Catalase: enzyme that breaks down hydrogen peroxide (toxic to our cells)
Found in liver cells
Chemical formula: 2H2O2 ----> 2H2O + O2

9. Catalase Lab: Safety Procedures
Safety goggles at all times
Gloves if you are handling hydrogen peroxide
Hair pulled back

10. Part A 2 mL of hydrogen peroxide into Test Tube 1
Add small piece of liver
Observe and record observations
After you have recorded observations, pour out hydrogen peroxide
2 mL of hydrogen peroxide into Test Tube 2
Add SAME piece of liver

11. Part B 2 mL of hydrogen peroxide into Test Tubes 3 & 4
Potato into Test Tube 3
Apple into Test Tube 4
Observe and record observations

12. Part C Piece of clean liver into Test Tube 5
Cover with distilled water
Boil for 5 minutes
Pour out water
Add 2 mL hydrogen peroxide
Observe and record observations

13. Part D
Use the image above to complete Part D of your Lab.

14. Analysis Questions 1-5

15. Enzyme-Substrate Complex
The substance (reactant) an enzyme acts on is the substrate
Enzyme
Joins
Substrate

16. Active Site
A restricted region of an enzyme molecule binds to the substrate.
LOCK AND KEY
Active Site
Enzyme
Substrate

17. Check Yo’ Self What was the substrate in the lab?
Hydrogen peroxide (H2O2)
What was the enzyme in the lab?
Catalase
Explain the chemical reaction that occurred as a result of the enzyme
Catalase broke down hydrogen peroxide into oxygen and water

18. What is the catalyst in this reaction?
What was the reactant? (APPLY KNOWLEDGE)

19. Enzyme + Substrate = Product

20. Competitive Inhibitor vs. Noncompetitive Inhibitor
A competitive inhibitor blocks the active binding site and prevents a reaction
Noncompetitive inhibitor attaches the enzyme and changes the shape of the active site