Natural macromolecules are large, complex molecules that are essential for life. They include proteins, nucleic acids, carbohydrates, and lipids. These macromolecules are made up of smaller units called monomers, which link together to form long chains. For example, proteins are made of amino acids, while nucleic acids like DNA are composed of nucleotides. These macromolecules play crucial roles in biological processes. Carbohydrates provide energy and structural support, while lipids are important for cell membranes and energy storage. Proteins perform a wide range of functions, including catalyzing reactions and providing structural integrity, and nucleic acids store and transmit genetic information.