double helix

A term used to describe the structure of DNA. Two polynucleotide strands, antiparallel in orientation, align by means of hydrogen bonds between DNA bases on opposite strands (base pairs). The strands assume a helical structure winding about each other to maximize the free energy released by the hydrogen bonding of the base pairs. The phosphodiester backbone faces outward in the aqueous environment.

References

Alperts et al Molecular Biology of the Cell, Garland Publishing, New York, NY 1989