antiparallel

  1. Adjective.  (mathematics) of vectors, parallel but of opposite direction.
  2. Adjective.  (biochemistry) describing the orientations of the two strands of DNA.
  3. Adjective.  (biochemistry) describing two beta strands comprising a protein's secondary structure that are aligned and hydrogen bonded but the vector describing the amino- and carboxy-terminal ends of each strand are oriented 180° relative to one another.
  4. Noun.  (geometry) A line that forms equal angles with two other lines, but in opposite directions.

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This entry was last updated on RefTopia from its source on 3/20/2012.