Spiral molecules, such as DNA, are a type of macromolecule that is composed of two strands of nucleotides twisted together in a helical shape. DNA is the most well-known example of a spiral molecule, and it is responsible for the storage and transmission of genetic information. DNA is composed of four different nucleotides: adenine, thymine, guanine, and cytosine. These nucleotides form the basis of the double helix structure of DNA, which is essential for the functioning of all living organisms.