Nucleic acid double helix

Structure formed by double-stranded molecules

In molecular biology, the double helix is the structure formed by double-stranded molecules of nucleic acids such as DNA. The double-helical structure of a nucleic acid complex arises as a consequence of its secondary structure, and is a fundamental component in determining its tertiary structure. The DNA double-helix biopolymer of nucleic acids is held together by nucleotides which base pair together. In B-DNA, the most common double-helical structure found in nature, the double helix is right-handed with about 10–10.5 base pairs per turn.

From Wikipedia, under CC BY-SA. More on occurri.