Photo AI
As apples ripen, enzymes convert starch into sugars - Edexcel - GCSE Biology - Question 2 - 2023 - Paper 1
Question 2
As apples ripen, enzymes convert starch into sugars. Devise a method to find the optimum pH of an enzyme that breaks down starch. You may use standard laboratory equ... show full transcript
Worked Solution & Example Answer:As apples ripen, enzymes convert starch into sugars - Edexcel - GCSE Biology - Question 2 - 2023 - Paper 1
Step 1
Devise a method to find the optimum pH of an enzyme that breaks down starch.
Answer
- Prepare Solutions:
- Prepare a range of pH solutions (e.g., pH 4 to pH 10).
- Include a starch solution and an enzyme solution specific for starch breakdown.
- Setup:
- In separate test tubes, add equal volumes of starch solution and enzyme solution.
- Add a different pH solution to each test tube and mix well.
- Incubate:
- Place the test tubes in a water bath at a constant temperature for a set time (e.g., 30 minutes).
- Test the Reaction:
- After incubation, add a few drops of iodine solution to each test tube.
- Iodine will change color (from brown to blue-black) in the presence of starch.
- Observe Results:
- The test tube that remains brown indicates the lowest amount of starch left, hence indicating the optimum pH where the enzyme activity is highest.
- Record and Analyze:
- Record the pH levels and the corresponding color changes, and identify which pH resulted in the least starch presence. This indicates the optimum pH for enzyme activity.