4.3 (a) To investigate the effect of pH on amylase activity
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Transcript of 4.3 (a) To investigate the effect of pH on amylase activity
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4.3 (a) To investigate the effect of pH on amylase activity
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Before you start get or make a copy of this
Table of results
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Step 1
Set up a water bath at 37 °C.
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Step 2
Place 5 ml starch solution and 3 drops of iodine solution into 3 boiling tubes.
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Step 3
Put 2 ml amylase solution and 5 ml buffer (4, 7, 9) into three other tubes.
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Step 4
Place all tubes into a water bath at 37 °C and leave for 5 minutes.
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Step 5
Pour one of the amylase tubes into one of the starch tubes. Gently
shake. Repeat for each pH.
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Step 6
Replace the tubes in the water bath and measure the time taken for the blue/black colour to disappear.
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Graph your results
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Step 7
Test for sugar: add 1ml Benedict’s solution to each boiling
tube and heat for 5 minutes.
Prepare as for steps 1 and 2
previously
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Step 8
A brick red colour indicates a reducing sugar is present.
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Step 9
Repeat the whole experiment with boiled amylase as a control.
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Expected result
The enzyme works best at a pH of 7.
The blue / black colour faded and Benedicts resulted in a positive
test.
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Results
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