There are four main types of biological molecules:
1. Carbohydrates: These are your body's main source of energy. They include sugars (like glucose) and starches. They're made of carbon, hydrogen, and oxygen, often in a 1:2:1 ratio.
2. Lipids: These are fats, oils, waxes, and steroids. They're good for long-term energy storage, insulation, and forming cell membranes. Lipids are mostly carbon and hydrogen, making them nonpolar (they don't mix well with water).
3. Proteins: These are the workhorses of the cell. They do almost everything! They act as enzymes (speed up reactions), transport substances, provide structural support, and fight infections. Proteins are made of smaller units called amino acids, linked together. They contain carbon, hydrogen, oxygen, and nitrogen, and sometimes sulfur.
4. Nucleic Acids: These carry genetic information. DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are nucleic acids. They're made of repeating units called nucleotides. These contain carbon, hydrogen, oxygen, nitrogen, and phosphorus.