LAB HELP - BREATHING AND RESPIRATION - To demonstrate that yeast respires

 TOPIC: BREATHING AND RESPIRATION 

AIM: To demonstrate that yeast respires

APPARATUS/MATERIALS:

·         2 boiling tubes

·         bung

·         delivery tube

·         glucose solution

·         yeast

POSSIBLE DISCUSSION QUESTIONS:

BACKGROUND

1.       Define respiration

2.       Name the two types of respiration

3.       State that yeast respires both aerobically and anaerobically.

4.       Which type of respiration takes place in this experiment?  How do you know?

5.       Write a word/chemical equation to represent the type of respiration in yeast.

6.       Which enzyme catalyzes respiration in yeast?

7.       What is the standard laboratory test for carbon dioxide? (Equation?)

8.       Which set-up serves as a control?  What is the purpose does the control serve in this experiment?


EXPLANTION OF RESULTS

10.   Compare expected results with experimental results

11.   How would you determine that anaerobic respiration did not take place?

      


PRECAUTIONS/LIMITATIONS/SOURCES OF ERROR

12.   Why is it important to use fresh yeast?

13.   Is it advisable to breathe near the tube containing lime water?