The sides, or backbone, of the DNA molecule are primarily made up of two types of molecules: deoxyribose sugar and phosphate.
Deoxyribose is a five-carbon sugar that contributes to the structure of DNA. It forms the core of the DNA backbone by linking with phosphate groups. Each deoxyribose sugar is attached to a phosphate group, creating a sugar-phosphate backbone. The phosphate groups connect to the 5′ carbon of one sugar and the 3′ carbon of the adjacent sugar, establishing a long chain that runs along the sides of the DNA.
Together, these molecules provide a stable and strong framework for the DNA structure, allowing the nucleotide base pairs (adenine, thymine, cytosine, and guanine) to attach in the center, holding the two strands of the DNA double helix together. This arrangement is crucial for the storage of genetic information and the replication process in living organisms.