What structural feature characterizes a double stranded helix?

A double-stranded helix is specifically characterized by the antiparallel arrangement of its strands. This means that one strand runs in the 5' to 3' direction while the complementary strand runs in the opposite direction, from 3' to 5'. This orientation is crucial for the proper pairing of the nucleotides across the two strands, which leads to the stable structure of the helix associated with DNA.

In a double-stranded helix, the base pairing occurs in such a way that the nucleotides on one strand are positioned to form hydrogen bonds with their complementary nucleotides on the opposite strand. The antiparallel configuration allows for these pairs to align correctly, enabling the double helix to maintain its structure and function effectively during processes such as DNA replication and transcription. The importance of this arrangement cannot be overstated, as it influences everything from the stability of the molecular structure to the fidelity of genetic information transfer.