# Explain why the products of carbohydrate digestion can be absorbed into the blood in the ileum but starch cannot.

> Pearson Edexcel International GCSE Biology (4BI1) — 2.6 Nutrition: humans · Explain · 4 marks

## Mark scheme (4 marks)

1. Starch is a large molecule / too large to pass through the wall of the ileum / too large to be absorbed
2. Starch is broken down / digested by amylase into maltose, and maltase breaks maltose into glucose
3. Glucose is a small / soluble molecule that can pass through the wall of the ileum
4. Glucose is absorbed by diffusion (or active transport) into the blood / into the capillaries in the villi

## Key terms

- [ileum](https://www.gradenine.co.uk/glossary/ileum)
- [starch](https://www.gradenine.co.uk/glossary/starch)

## Related

- [Revision notes for Pearson Edexcel International GCSE Biology (4BI1)](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-why-the-products-of-carbohydrate-f440c073) · Published by Druglandscape Ltd.