Nutrients: sources and functionsSpec 2.25
You need to know a source and a function for each of the nutrients in the table.
| Nutrient | Sources | Functions |
|---|---|---|
| Carbohydrate | Bread, pasta, rice, potatoes | Provides energy (released by respiration) |
| Protein | Meat, fish, eggs, beans | Growth and repair of tissues. Proteins are made from amino acids. |
| Lipid (fats and oils) | Butter, cooking oils, nuts, oily fish | Energy store, insulation (keeps heat in), and part of cell membranes |
| Vitamin A | Liver, carrots, dairy foods | Healthy eyes and vision in dim light. A lack causes night blindness. |
| Vitamin C | Citrus fruits, fresh vegetables | Keeps skin and gums healthy. A lack causes scurvy. |
| Vitamin D | Oily fish, eggs, margarine (also made in skin in sunlight) | Helps the body absorb calcium. A lack causes weak bones (rickets in children). |
| Calcium (mineral ion) | Milk, cheese, green vegetables | Needed for strong bones and teeth |
| Iron (mineral ion) | Red meat, liver, spinach | Needed to make haemoglobin in red blood cells. A lack causes anaemia. |
| Water | Drinks and most foods | Solvent for chemical reactions, and the main part of blood plasma, which transports substances |
| Dietary fibre | Wholemeal bread, vegetables, fruit | Adds bulk, which helps peristalsis move food through the gut and prevents constipation |
Exam tip:
Mark schemes want a specific function, not just 'it is good for you'. Learn one clear function for each nutrient. Fibre is not digested, so it provides no energy.