1. Cells live by Molecular Actions Laboratory Investigation into how molecules carry out Cell life processes

2. Cells

3. Molecules

4. H 2 O 2  2H 2 O + O 2

5. Brainstorm What changes during a chemical reaction? What stays the same during a chemical reaction? What is a catalyst? Examples?

6. Enzyme = Biological Catalyst Catalase active site

7. Let’s look at one Molecule in Cells Task 1: Observe Yeast Cells under the microscope. Task 2: Observe Catalase breakdown a cellular waste molecule (H 2 O 2 ); add Yeast/water suspension to Hydrogen Peroxide. Task 3: Carry out a plan to gather evidence about how Catalase works.

8. Task 1 Place one drop of yeast suspension on a microscope slide. Place cover slip over the top Observe first at low power, move to higher mag. Record and label what you see in your notebook (sketch, mag, description)

9. Task 2 Place 3 mL of H 2 O 2 into a test tube. Place 1 mL of yeast suspension (Catalase) into the test tube. Record your observations. What would happen if you doubled the amount of H 2 O 2 ? Catalase? – Record what you do; Record your results. Is Catalase reusable? How could you test this? – Record what you do; Record your results.

10. Task 3 Considerations Consider one of these factors: – Salinity (salt concentration) – Temperature – pH (we have 0.1 M HCl and 0.1 M NaOH) What will make for good scientific evidence? What change will you be looking for to show the activity of catalase? How much of each material will you use? Why? Record what you do and what you observe. This is your evidence.