# Explain why glucose is the monomer used to build carbohydrate polymers, and describe what happens to the water molecules released when these polymers are formed.

> AQA A-Level Biology (7402) — 3.1.2 Carbohydrates · Explain · 5 marks

> Carbohydrates are biological molecules made up of carbon, hydrogen, and oxygen. Simple sugars can be joined together to form long-chain polymers used for energy storage and structural support.

## Mark scheme (5 marks)

1. Glucose is a simple sugar / monosaccharide
2. Glucose molecules are joined together by condensation reactions
3. A water molecule is released / produced each time two monomers are joined
4. The water released can be used in hydrolysis reactions to break polymers back down into monomers
5. Glucose is suited as a monomer because it is small / soluble and can be transported easily / provides energy when respired

## Key terms

- [monomer](https://www.gradenine.co.uk/glossary/monomer)
- [polymer](https://www.gradenine.co.uk/glossary/polymer)

## Related

- [Revision notes for AQA A-Level Biology (7402)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-glucose-is-the-monomer-c609fab7) · Published by Druglandscape Ltd.