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A student mixed 10cm³ of starch solution with 5cm³ of amylase solution and kept the tube in a water bath at 25°C - Edexcel - GCSE Biology - Question 6 - 2020 - Paper 1
Question 6
A student mixed 10cm³ of starch solution with 5cm³ of amylase solution and kept the tube in a water bath at 25°C. The student tested the solution for starch and for... show full transcript
Worked Solution & Example Answer:A student mixed 10cm³ of starch solution with 5cm³ of amylase solution and kept the tube in a water bath at 25°C - Edexcel - GCSE Biology - Question 6 - 2020 - Paper 1
Step 1
Step 2
Step 3
Give one reason why this tube was included in their investigations.
Answer
The inclusion of the tube with distilled water instead of amylase allows for a control comparison to determine if any changes occur in the presence of amylase, demonstrating the enzyme's effectiveness in starch breakdown.
Step 4
Devise a method the students could use to confirm the optimum pH for amylase.
Answer
The students could set up a series of test tubes, each containing the same volume of starch solution and amylase, but at different pH levels (using buffer solutions). They would then measure the time taken for starch to be completely broken down by amylase in each tube, identifying the pH at which this occurs fastest as the optimum pH.
Step 5
Explain why amylase is not produced in the stomach.
Answer
Amylase is not produced in the stomach because the acidic environment (low pH) denatures the enzyme, rendering it inactive. Additionally, amylase is primarily secreted in saliva and by the pancreas, which are not present in the stomach.