1. Investigating Aerobic and Anaerobic Respiration

2. Background information: Yeast is a microscopic fungus that respires aerobically and anaerobically depending on the environment- very similar to humans Yeast – as well as humans- use glucose to produce chemical energy- ATP

3. Questions to answer: What substances are needed for cellular respiration to begin? (Look back at your notes if necessary to find the two molecules needed for your cells to produce energy) When cells or yeast cells go through cellular respiration- what three molecules are produced?

4. Problem? How can we design a lab to observe anaerobic respiration?

5. Hypothesis: If……….. Then………….

6. Lab Design You have the following materials to use to design an investigation to observe anaerobic respiration. How will you set up your lab? Materials: – 50 ml of apple cider – Balloon – 2 grams of yeast – Erlenmeyer flask

7. Safety Long pants Safety glasses Closed toe shoes

8. Variables Independent- Dependent- Control-

9. Procedures Gather necessary materials Measure 50 ml of apple cider and put into your Erlenmeyer flask. Add 2 grams of yeast to flask/cider Cover IMMEDIATELY with a balloon Let set. Record observations after 30 minutes and after 3 hours

10. Observations: What did you observe about your set up: – After 30 mins? – After 3 hours? Circumference after 30 minutes Circumference after 3 hours(min)

11. Conclusion: What did you observe about the balloon/flask set up on day one? Did your balloon inflate? If so, what substance filled the balloon? Briefly explain- using correct vocabulary terms- how the substance was produced. Did the yeast carry out aerobic or anaerobic respiration? How do you know? Did the control balloon inflate? Why or why not?