1. Peroxidase lab

2. What is peroxidase?  All organisms have enzymes (catalysts) called peroxidases that break down hydrogen peroxide into less harmful substance. Hydrogen Peroxide (H2O2) is a pale blue liquid that appears clear when diluted. Hydrogen peroxide is a weak acid that is used as a bleaching agent and disinfectant.

3. Do Learn Connect  Do: Peroxidase Lab  Learn: I can identify the products of a reaction and classify reactions in terms of energy.  Connect: Properties and Patterns, Energy

4. Question:  Will chicken liver react with hydrogen peroxide and if so what products are formed?

5. Hypothesis  If chicken liver reacts with hydrogen peroxide, then I will observe __________ (chemical reaction clues) and ____________ will be formed (products) because ______________________________ ______________________________ ______________________________ ______

6. Materials  Chicken Liver  Hydrogen Peroxide  Erlenmeyer Flask  Stopper  Toothpick  Candle

7. Procedure  Add Hydrogen Peroxide to flask.  Stopper the flask.  Record observations  Remove stopper from flask and insert toothpick into neck of flask. Do not drop it.  Record observations  Stopper flask.  Use the candle to ignite the toothpick, blow out the flame.  Remove stopper from flask and insert toothpick into neck of flask. Do not drop it.

8. Procedure  Add a small amount of chicken liver to the flask.  Stopper the flask.  Record observations.  After about 2 minutes, carefully feel the bottom of the flask.  Record Observations  Ignite the toothpick and blow out the flame.  Remove stopper and insert toothpick into the neck of the flask. Do not drop it.  Record observations.  Stopper the flask and repeat the last steps three more times.

9. Consider these questions:  Why did you make observations after each step?  What observations indicated that a chemical change took place? (Clues)  Classify the reaction as endothermic or exothermic using evidence.  What products were formed in this reaction?  Why is it important to replace the stopper quickly when it had been removed?

10. Products  The equation for the reaction is : 2H 2 O 2  ________ and ________

11. CER (Conclusion)  Claim: The chicken liver did react with the hydrogen peroxide forming ______________. (Products)  Evidence: During the chemical reaction, I observed ________________. (Clues)  Reasoning: Provide your own reasoning connecting your products and clues to chemical reactions. Pre-Ap should also connect to ENERGY.