1. Carbohydrates: These are made up of sugar molecules linked together. Examples include:

* Starch: Found in grains, potatoes, and other starchy foods. It's a complex carbohydrate that breaks down into glucose (sugar) for energy.

* Glycogen: This is the storage form of glucose in animals, found in the liver and muscles.

2. Proteins: Proteins are made up of long chains of amino acids. They are essential for building and repairing tissues, making enzymes, and many other vital functions. Examples include:

* Collagen: A major structural protein found in skin, bones, tendons, and cartilage.

* Hemoglobin: The protein found in red blood cells that carries oxygen throughout the body.

3. Fats (Lipids): Fats are made up of glycerol and fatty acids. They are a concentrated source of energy and also play important roles in cell structure and hormone production. Examples include:

* Triglycerides: The most common type of fat found in food and stored in the body.

* Cholesterol: A type of lipid found in animal products and produced by the body, essential for cell membranes and hormone production.