# Amylase is an enzyme that breaks down starch into simple sugars. Describe how the structure of amylase allows it to carry out this function, and explain what is meant by enzyme specificity.

> WJEC A-Level Biology (Wales) — 1.4 Biological reactions and enzymes · Describe and Explain · 5 marks

## Mark scheme (5 marks)

1. Amylase is a protein made from chains of amino acids
2. Amylase has an active site with a specific/complementary shape
3. Starch (the substrate) fits into the active site to form an enzyme-substrate complex
4. Enzyme specificity means amylase will only act on starch / only one substrate fits the active site
5. Amylase cannot break down other molecules (e.g. proteins/lipids) because their shape is not complementary to the active site

## Key terms

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

## Related

- [Revision notes for WJEC A-Level Biology (Wales)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe and Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/amylase-is-an-enzyme-that-breaks-b116f98c) · Published by Druglandscape Ltd.