Experiment 1: Enzymes in Food
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Table 1: Substance vs. Starch Presence |
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Substance |
Resulting Color |
Presence of Starch? |
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Positive Control: Ginger Root |
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Negative Control: Student Must Select |
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Food Product: |
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Food Product: |
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Saliva: |
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Post-Lab Questions
1. What were your controls for this experiment? What did they demonstrate? Why was saliva included in this experiment?
2. What is the effect of amylase when in contact with starch?What color would you expect tosee if, instead of starch, you used a sugar solution on your “saliva” paper towel? Why?
3. Which of the foods that you tested contained amylase? Which did not? How can you tell?
4. Identify three (3) other digestive enzymes and their respective substrates.
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Enzyme |
Substrate |
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5. Digestive enzymes in the stomach and intestines include proteases. What is the substrate for a protease? Why don’t these enzymes digest the walls of thestomach and small intestine?
Experiment 2: Effect of Temperature on Enzyme Activity
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Table 2: Balloon Circumference vs. Temperature |
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Tube |
Temperature (°C) |
Uninflated Balloon Circumference (cm) |
Final Balloon Circumference (cm) |
Difference in Balloon Circumference (cm) |
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1 – (Cold) |
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2 – (RT) |
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3 – (Hot) |
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Post-Lab Questions
1. What reaction is occurring in this experiment?
2. What is the enzyme in this experiment? What is the substrate?
3. What is the independent variable in this experiment? What is the dependent variable?
4. How did temperature affect enzyme function?
5. Is there a negative control in this experiment? If yes, identify the control. If no, how would you revise the experiment to include a negative control?
6. What is occurring if you increase the amount of substrate but see no increase in enzyme activity?
7. Design an experiment to determine the optimal operating temperature for the enzyme used in this experiment.
