1. Carbohydrates are composed of carbon, hydrogen, and oxygen atoms. They are the body's main source of energy and are found in foods such as bread, pasta, rice, fruits, and vegetables.

2. Proteins are composed of carbon, hydrogen, oxygen, nitrogen, and sulfur atoms. They are essential for building and repairing tissues and are found in foods such as meat, fish, eggs, dairy products, beans, and nuts.

3. Lipids are composed of carbon, hydrogen, and oxygen atoms. They are used for energy storage and insulation and are found in foods such as butter, margarine, oil, and nuts.

4. Nucleic acids are composed of carbon, hydrogen, oxygen, nitrogen, and phosphorus atoms. They are responsible for storing and transmitting genetic information and are found in all cells.