What type of biological macromolecule is DNA?

DNA, or deoxyribonucleic acid, is classified as a nucleic acid, which is one of the four main types of biological macromolecules. Nucleic acids are polymers made up of nucleotide monomers. Each nucleotide consists of a sugar, a phosphate group, and a nitrogenous base. The sequence of these nucleotides encodes genetic information, which is essential for the growth, development, and functioning of all living organisms.

In contrast, carbohydrates are primarily used for energy storage and providing structural support, proteins serve as enzymes, structural components, and play roles in signaling and defense, and lipids are important for energy storage, membrane structure, and signaling. These other macromolecules serve different functions in biological systems and have distinct structural characteristics compared to nucleic acids. Thus, identifying DNA as a nucleic acid accurately reflects its structure and function within cells.