Cellular Respiration Lab - Feeding Yeast

Cellular respiration lab-feeding yeast. The purpose of this experiment is to learn about anaerobic cellular respiration (fermentation).

 HYPOTHESIS: If I place yeast, sugar and water in a balloon, it will then expand or maybe explode.

 MATERIALS:

 Yeast

 Sugar

 Erlenmeyer Flask

 Luke warm water

 Measuring tape

 Balance

 Calculator

 Timer

 Balloon

 PROCEDURES:

1. Measure out 5 grams of yeast, 20 grams of sugar and 120 mL of Luke warm water.

2. Place yeast, sugar and water in Flask.

3. Quickly stretch the balloon over the opening of the flask.

4. Seal where the balloon and flask meet with tape.

5. Shake and allow the reaction to occur.

6. Measure the circumference of the balloon at three (3) minute intervals, and shake the flask again to further mix. Continue until asked to stop by instructor.

**DATA TABLE**

Time

(Min) Diameter

(cm) C/π Circumference

(cm)

3 min(Starting point of Reaction) 5.41 cm 17 cm

6 min 6.05 cm 19 cm

9 min 6.68 cm 21 cm

12 min 7.00 cm 22 cm

15 min 7.64 cm 24 cm

18 min 8.0 cm 25 cm

21 min 8.28 cm 26 cm

24 min 8.60 cm 27 cm

27 min(Ending point of reaction) 8.75 cm 27.5 cm

LAB QUESTIONS

1. Write down what you observe happening during this reaction.

 As I poured the sugar, yeast and warm water together, the balloon expanded.

2. Where did the gas come from? What do you think the gas is?

 The gas came from the yeast mixing with the hot water. The yeast is anaerobic respiration, meaning it doesn't contain