double helix

noun

: 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 between purine and pyrimidine bases compare alpha-helix, watson-crick model

double-helical

ˌdə-bəl-ˈhe-li-kəl 

-ˈhē-

adjective

Examples of double helix in a Sentence

Recent Examples on the Web

One of the challenges of working with ancient DNA samples is that damage accumulates over time, breaking up the structure of the double helix into ever smaller fragments. —John Timmer, Ars Technica, 11 July 2024

Her first breakthrough came in 1956, just three years after the double helix structure of DNA was understood. —Brian Murphy, Washington Post, 10 July 2024

The whole thing starts out with the two separate DNA double helices (or two locations of a single double helix) both inserted into the enzyme, with the DNA strands looking a bit like two U's with their bottoms facing each other. —John Timmer, Ars Technica, 26 June 2024

The story comes to us in two twisted strands, a double helix of past and present. —Ron Charles, Washington Post, 12 June 2024

Word History

First Known Use

1954, in the meaning defined above

Kids Definition

double helix

noun

: the arrangement in space of DNA that resembles a spirally twisted ladder with the sides made up of the sugar and phosphate units of the two nucleotide strands and the rungs made up of the pyrimidine and purine bases extending into the center and joined by hydrogen bonds

Medical Definition

double helix

noun

: 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 between purine and pyrimidine bases compare alpha-helix, watson-crick model

double-helical

-ˈhel-i-kəl  -ˈhē-li- 

adjective