Large molecules, also known as macromolecules, are complex structures made up of smaller units called monomers. These molecules can be found in various forms, including proteins, nucleic acids, carbohydrates, and lipids. Their size and structure play a crucial role in biological functions, as they are essential for processes like metabolism and cell signaling. In nature, large molecules are often formed through polymerization, where monomers bond together to create long chains. For example, DNA is a large molecule that carries genetic information, while proteins are made up of amino acids and perform numerous functions in living organisms. Understanding large molecules is vital for fields like biochemistry and molecular biology.