Double helix
The structure of DNA with the two strands of DNA spiraling about one other. The double helix looks something like an immensely long ladder twisted into a helix, or coil. The sides of the "ladder" are formed by a backbone of sugar and phosphate molecules, and the "rungs" consist of nucleotide bases joined weakly in the middle by hydrogen bonds. "The Double Helix" is the title of a excellent book by James Watson telling the story of his and Francis Crick's discovery of the correct model for DNA.

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double helix n a helix or spiral consisting of two strands in the surface of a cylinder that coil around its axis esp the structural arrangement of DNA in space that consists of paired polynucleotide strands stabilized by cross-links between purine and pyrimidine bases compare ALPHA-HELIX, WATSON-CRICK MODEL
dou·ble-he·li·cal -'hel-i-kəl, -'hē-li- adj

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Watson-Crick helix the usual configuration of double-stranded DNA in vivo, being two complementary antiparallel polynucleotide chains coiled into a helix, with the sugar-phosphate backbone on the outside and the two chains held together by hydrogen bonds between pairs of bases. The most common form is the classical right-handed helical B-DNA (q.v.), but alternative forms also exist, such as A-DNA and Z-DNA (qq.v.). See illustration at deoxyribonucleic acid.

Medical dictionary. 2011.

Look at other dictionaries:

  • double helix — double helix. См. двойная спираль [ДНК]. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • double helix — n technical a shape consisting of two parallel ↑spirals that twist around the same centre, found especially in the structure of ↑DNA …   Dictionary of contemporary English

  • double helix — ► NOUN ▪ a pair of parallel helices intertwined about a common axis, especially that in the structure of DNA …   English terms dictionary

  • double helix — n. the characteristic helical structure of the two complementary chains of nucleotides in DNA: the chains are linked by hydrogen bonds and coil around a single axis …   English World dictionary

  • Double helix — In geometry a double helix (plural helices ) typically consists of two congruent helices with the same axis, differing by a translation along the axis, which may or may not be half way. [ [http://demonstrations.wolfram.com/DoubleHelix/ Double… …   Wikipedia

  • double helix — noun a pair of parallel helices intertwined about a common axis the shape of the DNA molecule is a double helix • Hypernyms: ↑helix, ↑spiral * * * noun, pl ⋯ helices also ⋯ helixes [count] technical : the shape formed by two parallel lines that… …   Useful english dictionary

  • double helix — UK / US noun [countable] Word forms double helix : singular double helix plural double helixes or double helices biology the dna molecule that consists of two chains of nucleotides and has a shape like a twisted ladder …   English dictionary

  • double helix — dvivijė spiralė statusas T sritis chemija apibrėžtis Spiralė, susidedanti iš dviejų komplementarių antilygiagrečių DNR grandinių. atitikmenys: angl. double helix rus. двойная спираль ryšiai: sinonimas – dviguboji spiralė …   Chemijos terminų aiškinamasis žodynas

  • double helix — noun Date: 1954 a helix or spiral consisting of two strands in the surface of a cylinder that coil around its axis; especially the structural arrangement of DNA in space that consists of paired polynucleotide strands stabilized by cross links… …   New Collegiate Dictionary

  • double helix — Conformation of a DNA molecule like a ladder twisted into a helix …   Dictionary of molecular biology

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