# Explain why biological washing powders are able to remove food stains from clothes at lower washing temperatures than non-biological detergents, and state one limitation of using biological washing powders.

> Cambridge International IGCSE Biology (0610) — 21.2 Biotechnology · Explain · 4 marks

## Mark scheme (4 marks)

1. Biological washing powders contain enzymes (e.g. proteases, lipases, amylases) that break down stain molecules
2. Enzymes break down large, insoluble food molecules into smaller, soluble products that can be washed away
3. Enzymes are denatured / stop working at high temperatures, so a lower temperature is sufficient / high temperature is not needed
4. One limitation: enzymes may be denatured by high temperatures / may not work in very acidic or very alkaline water / may cause allergic reactions in some people

## Key terms

- [biological washing powder](https://www.gradenine.co.uk/glossary/biological-washing-powder)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-biological-washing-powders-are-7943c8d9) · Published by Druglandscape Ltd.