The four major macromolecules necessary for life are carbohydrates, lipids, proteins and nucleic acids. Carbohydrates are the most prevalent, and they are a source of immediate energy for living things.
Lipids are not water soluble and are a longer-term source of energy. Fats and oils are both lipids. Proteins include enzymes and antibodies as well as transport, regulatory and structural proteins. Proteins are crucial to many of life's functions, including growth, immunity and metabolism. Nucleic acids are responsible for storing and processing genetic data. The two types of nucleic acids are DNA and RNA.
A macromolecule is a large molecule made up of hundreds to thousands of atoms, much more than are in normal molecules.