# A group of adults took part in a health study. Those who reported eating a diet high in saturated fat had higher levels of low-density lipoprotein (LDL) cholesterol in their blood. Explain how a high level of LDL cholesterol in the blood increases the risk of a heart attack.

> Pearson Edexcel A-Level Biology A (9BI0) — 1.1 Cardiovascular disease and risk · Explain · 5 marks

> A group of adults took part in a health study. Those who reported eating a diet high in saturated fat had higher levels of low-density lipoprotein (LDL) cholesterol in their blood.

## Mark scheme (5 marks)

1. LDL cholesterol deposits build up inside the walls of coronary arteries (forming plaques / atheroma)
2. This narrows the lumen of the coronary arteries (reducing blood flow to the heart muscle)
3. A blood clot (thrombus) can form at the site of a plaque
4. The clot can completely block the coronary artery
5. Heart muscle cells are deprived of oxygen / glucose and so cannot respire, causing them to die — resulting in a heart attack

## Key terms

- [LDL cholesterol](https://www.gradenine.co.uk/glossary/ldl-cholesterol)
- [heart attack](https://www.gradenine.co.uk/glossary/heart-attack)

## Related

- [Revision notes for Pearson Edexcel A-Level Biology A (9BI0)](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/a-group-of-adults-took-part-6d67a7ad) · Published by Druglandscape Ltd.