DNA double helix

12 base pairs30 / 30 hydrogen bonds
Physics
60%
15%
Mean stretch0.0%
SequencePair 06 · T–A
5′
3′
3′
5′
Select a pair to inspect2 / 2 bonds
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CNOH
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About this model

12 complementary base pairs form two antiparallel strands. A–T pairs have two hydrogen bonds; G–C pairs have three.

Helicase opens the parental helix. Both polymerases read their templates 3′→5′ and synthesize new DNA 5′→3′. The leading strand grows toward the fork; lagging fragments grow away from it. After copying and schematic fragment joining, two daughter duplexes rewind and move apart, each with one original and one new strand.

Primers are assumed. Primer removal, ligase chemistry, topoisomerase, protein structures, geometry, and timing are simplified.

Three.js draws the molecules; Ammo.js springs connect nucleotides along each backbone and hydrogen-bond sites between the strands. Geometry and forces are schematic, rather than molecular dynamics.