# Explain how the structure of a monosaccharide enables it to be used in the synthesis of disaccharides and polysaccharides.

> IB DP Biology Standard Level (2023 syllabus) — B1.1 Carbohydrates and lipids · Explain · 4 marks

## Mark scheme (4 marks)

1. Monosaccharides contain hydroxyl (–OH) groups on their carbon skeleton
2. Two hydroxyl groups (one from each monosaccharide) react together, releasing a water molecule in a condensation reaction
3. A covalent glycosidic bond is formed between the two sugar units
4. This process can repeat many times because each monosaccharide has multiple –OH groups, allowing chain elongation to produce polysaccharides

## Key terms

- [monosaccharide](https://www.gradenine.co.uk/glossary/monosaccharide)
- [polysaccharide](https://www.gradenine.co.uk/glossary/polysaccharide)

## Related

- [Revision notes for IB DP Biology Standard Level (2023 syllabus)](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-how-the-structure-of-a-711e569d) · Published by Druglandscape Ltd.