Liquids Should Be 1 Finger Width High

Name:______Hour:______

Enzyme Lab

Purpose: To determine the job of an enzyme and how enzymes are affected by changes such as temperature and acidity

Procedure: . Set up the test tubes in a rack as shown in the first column. For example, put peroxide and a chunk of potato in the first test tube. . Liquids should be 1 finger width high. . Record results in second column based on the following scale: - 0 for no bubbles - 3 for fast bubbles - 1 for slow bubbles - 4 for very fast bubbles - 2 for moderate bubbles

Part I: Different Types of Potato

1. Peroxide (H2O2) + chunk potato Reaction: 0 1 2 3 4

2. Peroxide (H2O2) + ground potato Reaction: 0 1 2 3 4

3. Peroxide (H2O2) + boiled potato Reaction: 0 1 2 3 4

Part II: Different Types of Liver

4. Peroxide + chunk liver Reaction: 0 1 2 3 4

5. Peroxide + ground liver Reaction: 0 1 2 3 4

6. Peroxide + boiled liver Reaction: 0 1 2 3 4

Part III: Acid vs. Base

Allow a chunk of liver to sit in HCl or NaOH for 2-3 minutes before adding peroxide

7. Peroxide + chunk liver + HCl (acid) Reaction: 0 1 2 3 4

8. Peroxide + chunk liver + NaOH (base) Reaction: 0 1 2 3 4 Enzyme Lab Analysis

1. What is an enzyme?

2. Which substance(s) that we tested today contained enzymes? (Circle) Peroxide Potato Liver

3. What is a substrate?

4. What was the substrate that we used in lab today? (Circle) Peroxide Potato Liver

Part I: Different Types of Potato

5. Which tube had the greatest reaction? Why?

6. Why wouldn’t we expect a reaction with the boiled potato?

Part II: Different Types of Liver

7. Why would we expect a greater reaction with the ground liver than with the chunk of liver?

8. Why would we expect a greater reaction with the ground liver than with the boiled liver?

Part III: Acid vs. Base

9. What happened to the reaction when acid or base was added to the chunk of liver?

Summary 10. What does temperature do to enzymes? (Hint: think about the reaction of the boiled potato and boiled liver)

11. What do acids and bases do to enzymes? (Hint: think about Part III of the lab)

12. Why might someone with a fever have trouble digesting a large meal?