Catalase Lab

Chapter 2 - Biochemistry

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”)

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!

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

Example hypothesis

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

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

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!