1. Carbohydrates: These molecules are made up of carbon, hydrogen, and oxygen. They provide energy for living organisms and are found in foods like bread, pasta, and fruit. Examples include glucose, starch, and cellulose.

2. Lipids: These are fats, oils, and waxes that are composed mainly of carbon, hydrogen, and oxygen, but often contain a smaller proportion of oxygen than carbohydrates. They are important for energy storage, insulation, and cell membrane structure. Examples include triglycerides, phospholipids, and cholesterol.

3. Proteins: These are large, complex molecules made up of amino acids. They play many vital roles in the body, including building and repairing tissues, transporting substances, and fighting infections. Examples include enzymes, antibodies, and hormones.

4. Nucleic Acids: These are complex molecules responsible for storing and transmitting genetic information. They are made up of nucleotides, which are composed of a sugar, a phosphate group, and a nitrogenous base. Examples include DNA and RNA.