# A student is investigating the effect of temperature on the rate of enzyme activity using amylase and starch solution. Describe how the student should carry out this investigation safely and accurately, including how to collect valid results.

> OCR A-Level Biology B — Advancing Biology (H422) — 1.2 Practical skills assessed in the practical endorsement · Describe · 5 marks

> Amylase is an enzyme produced in the salivary glands and pancreas. It breaks down carbohydrates into simple sugars. The student tests starch solution at different temperatures using iodine solution to detect when starch has been broken down.

## Mark scheme (5 marks)

1. Use a water bath to control the temperature of the amylase and starch solution
2. Keep at least one variable constant throughout the investigation, such as the volume or concentration of amylase and starch
3. Use iodine solution to test for the presence of starch at regular time intervals, noting when the iodine no longer turns blue-black
4. Repeat the experiment at each temperature and calculate a mean to improve the reliability of results
5. State an appropriate safety precaution, such as wearing safety goggles when handling iodine solution or taking care with hot water baths

## Key terms

- [amylase](https://www.gradenine.co.uk/glossary/amylase)
- [enzyme](https://www.gradenine.co.uk/glossary/enzyme)

## Related

- [Revision notes for OCR A-Level Biology B — Advancing Biology (H422)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-is-investigating-the-effect-700f3c17) · Published by Druglandscape Ltd.