Cellular respiration and fermentation PDF

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Lab report for professor rami alsaber on cellular respiration and fermentation...

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Anissa Zibo Bio 210 Prof Alsaber

Introduction: Cellular respiration is how an organisms uses the energy they have stored from photosynthesis while fermentation is an anaerobic process in which energy can be released from glucose even though oxygen is not available. Hypothesis: For experiment 1, we tested fermentation in yeast using fruit juice. We hypothesized that the more carbon dioxide that was released the more the yeast was undergoing fermentation. For experiment 2 we hypothesized that fruit juices that are antioxidants would prevent apples from turning brown due to oxidation. Finally for experiment 3 we hypothesized that the change of temperature would result in a increased or decreased rate of fermentation rate in yeast. Materials: For experiment 1 we used a water bath, thermometer, fermentation tubes, distilled water, different fruit juices, pipettes,7 grams of active dry yeast, 600ml beakers, 50 ml beakers, 25 ml beakers, glass stirrer and pH paper. For experiment 2 we used lemon water, orange juice, grape juice, paper towel, a knife, distilled water and one fresh apple. For experiment 3 we used a water bath set at 42 degrees celsius, a thermometer, fermentation tubes, distilled water, sucrose, yeast suspension from experiment 1, a 600ml beaker, 2 50ml beakers, pipettes, 25ml graduated cylinder, glass stirrers and an ice bath. Procedure: For experiment one we first mixed 7 grams of yeast in 200 ml of warm distilled water. Then we pre warmed all juice to 42 degrees celsius.Next we labeled two 50 mL beakers

1 and 2. To beaker 1, we added 18 mL of distilled water. To beaker 2 we added the volume of juice that had 2 grams of sugar and then added distilled water to make the volume 18ml. Next we determined the pH of the juice and recorded it. To each beaker we added 2 ml of yeast suspension and we stirred it. Next we added each of the 20ml mixtures into fermentation tubes 1 and 2. We then inverted each tube to remove the air from the vertical arm. After we set each fermentation tube in a water bath set at 42 ° C. For experiment 2 we first cut up four apple slices at the same size. Them we dipped each slice in distilled water, lemon juice, orange juice and grape juice. Then we set each slice side by side on a paper towel. Every 5 minutes we observed the color changes for 20 minutes and recorded. For the final experiment we labeled two 50 mL beakers 1 and 2. We also labeled two fermentation tubes 1 and 2. To beaker 1, we added 18 mL of distilled water and to beaker 2, we dissolved 2 g of sucrose in a total volume of 18 mL. To each beaker, we added 2 mL of the yeast suspension from Activity 1 and stirred. Next, we poured each 20 mL sample in the separate fermentation tubes (1 and 2) and finally inverted each tube to remove the air from the vertical arm. Results/ Observation: Activity 1:

PH

Displacement

Volume

Orange

4

8

14.13

Apple

4

9

15.97

cranberry

3

4.5

5.97

grape

3

7

12.36

pineapple

4

6.9

14.6

Fruit punch

4

7

9.29

lemon

2

0

0

control

6

0

0

Activity 2:  5 min 10 min 15 min 20 min 25 min 30min water

1

2

3

3

4

4

lemon

1

1

1

1

1

1

orange

1

2

2

2

2

2

grape

1

1

1

1

1

1

Activity 3: Degrees celsius

displacement

volume

4

0

0

23

1.5

2

42

6.5

8.6

For experiment 1 , we observed that the highest displacement of liquid was apple and orange juice and also had the highest volume of carbon dioxide production. Lemon juice was the lowest in all categories and its runner up was cranberry juice. For experiment 2 we observed that the intensity of the discoloration of the apple slices rose significantly with water, but did not change at all with lemon and grape juice. For experiment 3, we observed that the higher the temperature was raised the more carbon dioxide was produced. Conclusion: In conclusion we found out how and what affects fermentation. Antioxidants And temperature are two components of the same relationship in regards to fermentation. Temperature plays an important role in controlling the growth of microorganisms during fermentation, and the growth of microorganisms can influence the activity of antioxidants....