Exercise 8: Chemical and Physical Processes of Digestion: Activity 1: Assessing Starch Digestion by Salivary Amylase Lab Report
Pre-lab Quiz Results You scored 100% by answering 6 out of 6 questions correctly.1. The substrate for amylase is
You correctly answered: e. starch and carbohydrate.
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Which of the following is true of enzymes? You correctly answered: c. Their activity can be affected by temperature and pH.
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The reagent IKI tests for the presence of You correctly answered: a. starch.
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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
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Which of the following is an end product of starch digestion? You correctly answered: e. maltose and glucose
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Hydrolases are enzymes that break down large molecules into smaller subunits through the addition of _____. You correctly answered: b. water
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. Reagent 1 Reagent 2 Reagent 3 Treatment Time Temp. IKI Benedict’s 1 Amylase Starch pH 7.0 Buffer Boiled 60 37 + – 2 Amylase Starch pH 7.0 Buffer Frozen 60 37 – ++ 3 Amylase Starch pH 7.0 Buffer None 60 37 – ++ 4 Amylase Deionized Water
pH 7.0 Buffer None 60 37 – –
5 Deionized Water
Starch pH 7.0 Buffer None 60 37 + –
6 Deionized Water
Maltose pH 7.0 Buffer None 60 37 – ++
7 Amylase Starch pH 2.0 Buffer None 60 37 + + 8 Amylase Starch pH 9.0 Buffer None 60 37 + +
Review Sheet Results
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List the substrate and the subunit product of amylase. Your answer: The substrate of amylase is animal starch and the subunit product of amylase are maltose and glucose.
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What effect did boiling have on enzyme activity? Why? How well did the results this compare with your prediction? Your answer: Boiling altered the enzyme and deactivated the amylase activity as I predicted.
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At what pH was the amylase activity the most active? Describe the significance of this result. Your answer: The amylase activity was most active at pH 7.0. This is significant because this is the same pH as the mouth.
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Briefly describe the need for controls and give an example used in this activity. Your answer: Controls are vital as they are used to verify results of the experiment. For example take test tube #5 where the enzyme that tests for contaminating glucose in the starch is absent.
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Describe the significance of using a 37°C incubation temperature to test salivary amylase activity. Your answer: The significance of using 37 degrees C on account of this temperature is the same as human body temperature therefore it is ideal for the salivary amylase activity.