DNA (deoxyribonucleic acid) is a large molecule that is essential for life. It encodes the genetic instructions for the development and functioning of living organisms and viruses.
Most DNA molecules are made of two polymer chains in the form of a double helix. The chains are made from four different monomers called nucleotides.
Other naturally occurring polymers are also important for life. Proteins are polymers made from amino acids. Starch and cellulose are polymers made from simple sugars, such as glucose.
