Pepsin Enzyme
Purpose:
Different enzymes work best under different conditions. The purpose of this experiment is to determine the optimum ph level for the enzyme pepsin.
The enzyme pepsin is an enzyme found in the stomach that helps break down and digest food. Knowing where the pepsin is found led to the hypothesis that the enzyme worked best in conditions with lower pH levels around 1, as these are the conditions found in the stomach.
Materials Used:
Procedure:
1. Label six test tubes 1 – 6.
2. Using a graduated pipette, place 5 cm3 of egg-white suspension in each tube.
3. Using a graduated pipette, place 1 cm3 of acid or alkali in each tube using the table below as a guide.
4. Prepare a water bath in a beaker by mixing hot and cold water from the tap to give a temperature of about 40°C.
5. Use a graduated pipette to add 1 cm pepsin solution to each tube, and start a stopclock. Time how long it takes for each tube to go clear.
6. Compare the pH of each tube by testing the pH with a pH scale. Repeat for each tube, rinsing the pipette between samples.
Results:
PH level State Of Egg Whites
0 Very clear almost transparent
1.7 Mostly clear, areas of cloudyness
3.2 Half clear half clody
4.6 Mostly cloudy with areas or transparency
5.6 Very cloudy
7 Appeared to be unchanged
Conclusion:
As our hypothesis suggested, the pepsin worked best under the lowest pH level. The egg whites placed in the lowest ph level with pepsin turned the clearest because the pepsin was more productive in breaking the whites down under the conditions closest to that of the stomach.
Different enzymes work best under different conditions. The purpose of this experiment is to determine the optimum ph level for the enzyme pepsin.
The enzyme pepsin is an enzyme found in the stomach that helps break down and digest food. Knowing where the pepsin is found led to the hypothesis that the enzyme worked best in conditions with lower pH levels around 1, as these are the conditions found in the stomach.
Materials Used:
- Egg whites
- Test tubes
- Pepsin
- Acid
- Water
- Beakers
- pH tester
Procedure:
1. Label six test tubes 1 – 6.
2. Using a graduated pipette, place 5 cm3 of egg-white suspension in each tube.
3. Using a graduated pipette, place 1 cm3 of acid or alkali in each tube using the table below as a guide.
4. Prepare a water bath in a beaker by mixing hot and cold water from the tap to give a temperature of about 40°C.
5. Use a graduated pipette to add 1 cm pepsin solution to each tube, and start a stopclock. Time how long it takes for each tube to go clear.
6. Compare the pH of each tube by testing the pH with a pH scale. Repeat for each tube, rinsing the pipette between samples.
Results:
PH level State Of Egg Whites
0 Very clear almost transparent
1.7 Mostly clear, areas of cloudyness
3.2 Half clear half clody
4.6 Mostly cloudy with areas or transparency
5.6 Very cloudy
7 Appeared to be unchanged
Conclusion:
As our hypothesis suggested, the pepsin worked best under the lowest pH level. The egg whites placed in the lowest ph level with pepsin turned the clearest because the pepsin was more productive in breaking the whites down under the conditions closest to that of the stomach.