1. Chapter 2 - Biochemistry
Catalase Lab
Chapter 2 - Biochemistry

2. Review from Friday, first. (Verbal only)
What are proteins made of?
What are enzymes and what do they do?
What is the “lock and key” all about? Use “amylase” and “starch” in your answer.
What happens if an enzyme’s shape changes (becomes “denatured”)

3. Catalase Lab! Paraphrase in your notebook
Catalase is an enzyme (speeds up a reaction)
Present in most cells, high quantities in liver
Breaks down hydrogen peroxide (cell waste, poison)
Speed affected by temperature
Reaction:
hydrogen peroxide changed into water and oxygen bubbles
2H2O2  2H20 + O2
DEMO!

4. Your task:
Design an experiment that answers the question, “How does temperature affect the rate at which catalase breaks down hydrogen peroxide?”
Every student will need to develop and write his or her own experimental design.
Lab groups will complete the lab together
Write down a formal hypothesis now
I’ll call on students to read theirs in a moment
You may work with your neighbor

5. Example hypothesis
If the temperature _____________, then the speed of the catalase reaction will ___________ because __________________________.

6. Experimental Design Pass out rubric, lab report guidelines
Review the experimental design rubric now
Mr. Welman will demonstrate the technique now. Take notes on what he does.
Control group: 50 mL of catalase at room temperature (20 deg C)
3 warmer temperatures of catalase will also be available – 400 mL of each
(leave temps blank for now)
Use 100 mL of hydrogen peroxide per trial
3 times (3 trials), then pour down the drain
Questions? Ask them when he’s done

7. Lab work
With your partner, discuss the variables, materials, and procedure you will write.
2 min, then I’ll take questions
Experimental design due on Thursday
Here’s the format you should use (online)
Start working on your experimental design right now – on a new page in your notebook.
Your procedure should be clear enough for another student to complete, even if they were unfamiliar with the lab.
Take your time. Low effort = more work later
Test-taking seats!