# Explain how the molecular structure of cellulose makes it well suited to its function as a structural component of plant cell walls.

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

## Mark scheme (4 marks)

1. Cellulose is composed of glucose monomers/subunits linked by glycosidic bonds
2. The β-1,4-glycosidic linkages cause alternating glucose units to be flipped/inverted, allowing the chain to remain straight/unbranched
3. Hydrogen bonds form between parallel cellulose chains, bundling them into microfibrils
4. The resulting microfibrils provide high tensile strength, preventing the cell wall from bursting under osmotic pressure / providing mechanical support to the cell

## Key terms

- [cellulose](https://www.gradenine.co.uk/glossary/cellulose)
- [cell wall](https://www.gradenine.co.uk/glossary/cell-wall)

## 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)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-the-molecular-structure-of-89d3c235) · Published by Druglandscape Ltd.