Human Nutrition & Transport

What this lesson covers

Human Nutrition & Transport is a 8-part O Level Biology lesson. Each part makes one point and then hands over to the next, so it can be read in a sitting or picked up again at the part you stopped on. It defines the idea in plain words before using it, works through an example step by step, breaks the topic into its parts and compares them, shows where it is used outside the textbook, names the mistakes that cost marks in an exam, ends with a recap of what to remember.

How it begins

Seven components: carbohydrates (energy), proteins (growth and repair), fats (energy store, insulation, membranes), vitamins, minerals, fibre and water. The deficiencies the syllabus names: vitamin C → scurvy (bleeding gums, poor wound healing); vitamin D → rickets, because vitamin D is needed to absorb calcium; calcium → weak bones and teeth; iron → anaemia, because iron is needed to make haemoglobin.

The 8 parts

1. A balanced diet, and what happens without each part
2. Digestion: the organs, the enzymes and bile
3. Absorption, and why the villus looks the way it does
4. The heart and the double circulation
5. Blood, and the diseases the syllabus names
6. Where marks go
7. What to remember
8. Watch one worked through