Organic molecules like carbohydrates, lipids, proteins, and nucleic acids are composed of carbon and generate life's form and function. They contain monomers that link together through dehydration synthesis to form polymers. Carbohydrates function as fuels and structural components, lipids are hydrophobic and store energy, proteins assist in cell functions, and nucleic acids store and use genetic information. These macromolecules contain functional groups and are essential to all living things.