1. Carbohydrates: These are sugars and starches that serve as the primary source of energy for cells. They also provide structural support and play a role in cell signaling. Examples include glucose, glycogen, and cellulose.

2. Lipids: These are fats, oils, and waxes that provide long-term energy storage, insulation, and form the structural components of cell membranes. Examples include phospholipids, triglycerides, and cholesterol.

3. Proteins: These are large, complex molecules that perform a wide variety of functions in cells, including catalyzing reactions (enzymes), transporting molecules, providing structural support, and regulating cell processes. Examples include enzymes, antibodies, and hormones.

4. Nucleic Acids: These are complex molecules that carry genetic information (DNA) and direct protein synthesis (RNA). Examples include DNA and RNA.

These four types of molecules are essential for all living organisms and work together to maintain life processes.