The unit in one line
The molecules plants are built from and run on: sugars, fats, minerals, proteins and the enzymes that drive every reaction. 2 of Botany's 40 questions, over two chapters, and the base that respiration, photosynthesis and genetics build on later.
Read in this order
- Carbohydrates, lipids and minerals (9 min) — mono-, di- and polysaccharides with their linkages, the lipid classes, and the macro- and micronutrients with the deficiency each causes.
- Proteins and enzymes (9 min) — the four levels of protein structure, the enzyme classes, lock-and-key against induced fit, and competitive against non-competitive inhibition.
About 20 minutes in all.
How it is asked
MEC sets the paper roughly half recall, a third understanding and a fifth application. Recall here is linkages, examples and deficiency symptoms (which element, which leaves first). Understanding is why starch and cellulose behave so differently though both are made of glucose, or why more substrate overcomes a competitive inhibitor. Application is reading a described deficiency symptom or an enzyme-rate experiment.
Then practise
Each chapter has a fixed-length chapter test under Practice › Topics, drawn from questions written to that chapter's scope. Sit it after reading; a second sitting a week later shows whether it stuck.