Describe how glucose and amino acids are absorbed from the ileum into the bloodstream.

Cambridge International IGCSE Biology (0610) — 7.5 Absorption · Describe · 4 marks · View as Markdown

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

Model answer (4 marks)

1. Glucose and amino acids move from the lumen of the ileum through the intestinal wall into the bloodstream.
2. The villi of the ileum increase the surface area available for absorption.
3. Microvilli on the surface of the epithelial cells further enlarge the absorptive area.
4. Once absorbed, glucose and amino acids are carried in the blood to cells where they are assimilated.

Examiner tips

Use the word "move" or "pass" to show transport. Mention both villi and microvilli as surface‑area enhancers. State the final destination (blood and then cells).

Common mistakes

Confusing the direction of transport (lumen to blood). Omitting either villi or microvilli. Using vague terms like "taken up" without specifying the bloodstream.

Mark scheme (4 marks)

Glucose and amino acids pass through the wall of the ileum (intestine) into the blood
The villi increase the surface area for absorption
Microvilli on the epithelial cells further increase the surface area for absorption
The absorbed glucose and amino acids are then transported in the blood to cells where they are assimilated

Key terms in this question

ileum