Explain how drinking too much alcohol over many years can damage the liver and affect the rest of the body.

Eduqas GCSE Biology — 3.4 Non-communicable diseases in humans · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (4 marks)

Alcohol is metabolised in the liver by alcohol dehydrogenase and CYP2E1.
Long‑term excess alcohol causes hepatocyte damage and death, leading to fibrosis and cirrhosis.
A damaged liver cannot efficiently remove toxins such as ammonia, bilirubin and acetaldehyde.
The accumulation of these toxins in the blood harms other organs and disrupts body systems.

Examiner tips

Use the exact terms ‘metabolised’, ‘fibrosis’, ‘cirrhosis’, ‘toxic substances’
Show the causal chain: alcohol → liver damage → toxin build‑up → systemic effects
Keep each point brief but complete

Common mistakes

Confusing liver damage with alcohol itself, e.g. saying ‘alcohol destroys the liver’ instead of ‘liver cells are damaged’
Omitting the role of toxin removal or the systemic impact

Mark scheme (4 marks)

Alcohol is broken down / metabolised in the liver
Long-term excessive alcohol consumption causes liver cells to be damaged or destroyed / replaced by scar tissue (cirrhosis)
Damaged liver cannot carry out its normal functions effectively, such as removing toxins from the blood
Toxins / harmful substances build up in the blood and can damage other organs / affect other body systems

Key terms in this question

liver