Cambridge IGCSE Biology 0610 · Chapter 7
Human Nutrition
Human nutrition follows one connected journey, and most of the marks in this chapter come from being able to say exactly where you are in it: a balanced diet supplies what the body needs, that food is ingested and moved along the alimentary canal, physical digestion breaks it into smaller pieces, chemical digestion converts it into small soluble molecules, absorption moves those molecules into the blood and lymph, and whatever is left over is egested. Learn the chapter as that sequence and most of the ‘which topic is this question actually testing’ confusion disappears on its own.
Cambridge splits this material into five syllabus sections — 7.1 Diet, 7.2 the digestive system, 7.3 physical digestion, 7.4 chemical digestion, and 7.5 absorption — and the pages below follow that same structure, with two topics broken out on their own because they carry enough independent depth to earn it: human teeth, and bile. Core candidates need diet, the digestive system, physical digestion, teeth, chemical digestion, and the core layer of digestive enzymes and absorption. Supplement candidates add the deeper enzyme detail — starch digestion, pepsin and trypsin — together with bile and the structure of a villus.
The biology itself is not hard to follow. Where students actually lose marks is precision: writing “digested” when the question is really asking about absorption, saying bile “breaks down fat” when it only breaks fat up, or answering a question about physical digestion with a fact about chemical digestion. Every page below is written to close exactly that kind of gap — not more facts, but the specific wording and causal chains a Cambridge mark scheme is actually built around.
What’s in this chapter
| Page | Level | What it covers |
|---|---|---|
| Diet | Core | What a balanced diet actually requires, the source and importance of each named nutrient, and the exact links behind scurvy and rickets. |
| The digestive system | Core | The alimentary canal and the four associated organs that feed into it, plus the five words — ingestion, digestion, absorption, assimilation, egestion — examiners keep separate. |
| Physical digestion | Core | Why breaking food into smaller pieces changes nothing chemically, and how that alone makes chemical digestion faster. |
| Human teeth | Core | The four tooth types matched to their function, and the fixed enamel–dentine–pulp structure examiners expect you to name in order. |
| Chemical digestion | Core | How large insoluble molecules become small soluble ones, traced meal by meal from mouth to small intestine, plus hydrochloric acid’s two required jobs. |
| Digestive enzymes | Core & Supplement | Amylase, protease and lipase — their exact substrates and products — plus the Supplement detail behind starch digestion and pepsin versus trypsin. |
| Bile | Supplement | Bile’s two separate jobs — emulsifying fat and neutralising stomach acid — and why neither one makes it an enzyme. |
| Absorption | Core & Supplement | Where nutrients and water actually leave the gut, and how villi, microvilli and the villus itself are built for exactly that job. |
Core or Supplement?
Diet, the digestive system, physical digestion, human teeth, and chemical digestion are Core throughout, so every candidate needs them regardless of tier. Digestive enzymes and absorption are mixed — the enzyme table, the secretion and action sites, and the basic absorption sites are Core, while starch digestion, pepsin and trypsin by name, villi and microvilli, and the detailed structure of a villus are Supplement only. Bile is Supplement in full, since both of its roles — emulsification and neutralisation — sit outside the Core syllabus. If you’re not certain which tier you’re sitting, it’s worth checking before spending time on the Supplement pages, since none of the Core material depends on them.