Exercise 8: Chemical and Physical Processes of Digestion: Activity 1: Assessing Starch Digestion by Salivary Amylase Lab
Report
Pre-lab Quiz Results
You scored 83% by answering 5 out of 6 questions correctly.
1. The substrate for amylase is
Your answer : b. starch.
Correct answer: e. starch and carbohydrate.
2. Which of the following is true of enzymes?
You correctly answered: c. Their activity can be affected by temperature and pH.
3. The reagent IKI tests for the presence of
You correctly answered: a. starch.
4. Which of the following is not true of controls?
You correctly answered: d. A negative result with a positive control is required to validate the test
5. Which of the following is an end product of starch digestion?
You correctly answered: e. maltose and glucose
6. Hydrolases are enzymes that break down large molecules into smaller subunits through the addition of _____________.
You correctly answered: b. water
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Experiment Results
Predict Question:
Predict Question: What effect do you think boiling and freezing will have on the activity of the amylase enzyme?
Your answer : c. Boiling will decrease amylase activity and freezing will have no effect.
Stop & Think Questions:
Tube 2 appears to have the same amount of starch digested as tube 3 because
You correctly answered: a. freezing had no effect on the enzyme.
Experiment Data:
Tube No.
1
2
3
4
Reagent 1
Amylase
Amylase
Amylase
Amylase
5
Deionized
Water
Deionized
Water
pH 2.0 Buffer
Amylase
6
7
8
Reagent 2
Starch
Starch
Starch
Deionized
Water
Starch
Reagent 3 pH 7.0 Buffer pH 7.0 Buffer pH 7.0 Buffer pH 7.0 Buffer
Treatment
Boiled
Frozen
None
None
Time
60
60
60
60
Temp.
37
37
37
37
IKI
+
-
Benedict's
++
++
-
pH 7.0 Buffer
None
60
37
+
-
Maltose
pH 7.0 Buffer
None
60
37
-
++
Starch
Starch
Amylase pH 9.0 Buffer
None
None
60
60
37
37
+
+
+
+
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Post-lab Quiz Results
You scored 100% by answering 4 out of 4 questions correctly.
1. Tubes 3, 7, and 8 reveal that
You correctly answered: d. amylase activity was highest at pH 7.
2. This activity includes a number of negative controls. Which tube indicates that the amylase solution was not contaminated with maltose?
You correctly answered: b. tube 4
3. Which tubes indicate that the deionized water did not contain contaminating starch or maltose?
You correctly answered: c. tubes 4, 5, and 6
4. Explain where and why salivary amylase would be most active.
You correctly answered: d. Salivary amylase would be most active in the mouth because pH 7 is where its peak activity is.
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Review Sheet Results
1. List the substrate and the subunit product of amylase.
Your answer: amylose and glucose
2. What effect did boiling have on enzyme activity? Why? How well did the results this compare with your prediction?
Your answer: boiling decreased the overall activity of the enzyme. enzymes function in a specific environment based on our body temp.
3. At what pH was the amylase activity the most active? Describe the significance of this result.
Your answer: the pH at which anylase is most active is pH 7.0. This pH is found in areas where starch digestion occurs.
4. Briefly describe the need for controls and give an example used in this activity.
Your answer:
The use of controls allows us to ensure our test solutions are not contaminated. Examples include: Testing for sugar using
Benedict's test on Amylase and deionized water ensures that the deionized water or Amylase was not contaminated with maltose. 5. Describe the significance of using a 37°C incubation temperature to test salivary amylase activity.
Your answer:
37 degrees is the average temperature of the body
04/08/15
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