A student mixed 10 cm³ of starch solution with 5 cm³ of amylase solution and kept the tube in a water bath at 25°C - Edexcel - GCSE Biology Combined Science - Question 4 - 2020 - Paper 1
Question 4
A student mixed 10 cm³ of starch solution with 5 cm³ of amylase solution and kept the tube in a water bath at 25°C.
The student tested the solution for starch and f... show full transcript
Worked Solution & Example Answer:A student mixed 10 cm³ of starch solution with 5 cm³ of amylase solution and kept the tube in a water bath at 25°C - Edexcel - GCSE Biology Combined Science - Question 4 - 2020 - Paper 1
Step 1
Give one reason for the result at 150 seconds.
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Answer
At 150 seconds, all the starch has been converted into glucose due to the action of the amylase enzyme. This means that there is no starch left to be detected, resulting in a negative test for starch.
Step 2
Give two other variables that would need to be controlled in the investigation.
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Answer
pH of the solution should be controlled to ensure optimal enzyme activity.
Concentration of amylase should be kept constant to avoid variations in reaction rate.
