The
secondary structure of a nucleic acid molecule refers to the
basepairing interactions within a single molecule or set of interacting molecules, and can be represented as a list of bases which are paired in a nucleic acid molecule. The secondary structures of biological
DNA's and
RNA's tend to be different: biological DNA mostly exists as fully
base paired double helices, while biological RNA is single stranded and often forms complicated base-pairing interactions due to its increased ability to form
hydrogen bonds stemming from the extra
hydroxyl group in the
ribose sugar.