# Starch is a carbohydrate found in foods such as bread and pasta. Describe how the body uses enzymes to break down starch, including where these enzymes are produced, what they break starch down into, and how the 'lock and key' hypothesis explains their action.

> Eduqas A-Level Biology — 1.1 Chemical elements and biological molecules · Describe · 5 marks

## Mark scheme (5 marks)

1. Amylase / carbohydrase is the enzyme that breaks down starch
2. Amylase is produced in the salivary glands and/or pancreas
3. Starch is broken down into simple sugars
4. The active site of the enzyme has a specific / complementary shape to the starch substrate
5. Only starch (and not other substrates) can fit into amylase's active site, explaining enzyme specificity / the lock and key hypothesis

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