CAIE IGCSE Biology 3.3.1 Definition of Active Transport
Practise stating and recognising active transport as energy-dependent particle movement against a concentration gradient.
- Syllabus
- 2026–2028
- Course
- Biology 0610
Practise stating and recognising active transport as energy-dependent particle movement against a concentration gradient.
Fig. 1.1 shows several villi from the ileum, which is part of the small intestine.
Fig. 1.2 shows the tip of a villus in more detail.

Fig. 1.2
The epithelial cells of the villi absorb nutrients by diffusion and active transport.
Describe how active transport differs from diffusion.
any three from:
ref. to membrane for active transport ;
uses (chemical) energy ;
energy from, the cell / respiration / mitochondria ;
(substances move) against concentration gradient / low to high concentration ; using / AW, proteins / carriers (in membranes) ;