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

Photograph: Peter Fisher At one point, Bailey sketched an idea around a double helix shape. —Joseph Bien-Kahn, WIRED, 19 Sep. 2024

The key shows the universal elements (hydrogen, oxygen, carbon and nitrogen), the four bases of the DNA molecule (adenine, cytosine, guanine and thymine) with their molecular structure, where they’re placed in the DNA double helix, and how genes are arranged on a chromosome. —New Atlas, 19 Sep. 2024

Li says that her book is structured like a double helix, with her personal quest and the trajectory of AI intertwined into a spiraling whole. —Steven Levy, WIRED, 13 Sep. 2024

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

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