3.1 Types of Biological Molecules
- Carbohydrates: Energy source and storage.
- Proteins: Growth, repair, enzymes.
- Lipids: Energy storage, insulation.
- Nucleic Acids: Store genetic information.
| Type | Examples | Function |
|---|
| Carbohydrates | Glucose, Starch, Glycogen | Energy storage, structure |
| Proteins | Enzymes, Hemoglobin | Growth, repair, enzymes |
| Lipids | Fats, Oils | Energy storage, insulation |
| Nucleic Acids | DNA, RNA | Genetic information storage |
3.2 Carbohydrates
- Monosaccharides: Simple sugars (e.g., glucose).
- Polysaccharides: Starch (plants), Glycogen (animals), Cellulose (plant cell walls).
3.3 Proteins
- Made of amino acids.
- Enzymes: Catalysts in biochemical reactions.
3.4 Lipids
- Made of glycerol and fatty acids.
- Function: Energy storage, protection.
3.5 Water
- Functions of Water:
- Solvent, temperature regulation, metabolic reactions.
3.6 Food Tests
- Test for Starch: Iodine solution → Blue-black color.
- Test for Reducing Sugars: Benedict’s solution → Brick-red precipitate on heating.
- Test for Proteins: Biuret solution → Purple color.
- Test for Lipids: Ethanol (emulsion test) → Milky white emulsion.