🧬 DNA Replication Lab

Mission: copy DNA accurately

Open the parental helix, copy both templates in the 5′ to 3′ direction, join lagging fragments, and watch two matching DNA molecules emerge.
Unzip
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Prime
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Copy
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Join
Old strandNew strandHelicasePolymerasePrimerLigase
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Replication conditions

1.0×
100%
95%
0%DNA copied
0fragments joined
0errors remaining

Replication evidence

Blue: DNA copied · Red: errors detected · Green: errors corrected

Tracked object

No object selected
TipTap helicase, polymerase, primer, fragment, or ligase

Camera

100%

Teacher tools

Teacher-guided complete lecture

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Ready0%
What to watch: each spoken event is demonstrated and highlighted.
Choose a language and voice, then begin. The replication fork will change automatically with every chapter.
Ready. Narration will not start automatically.

Chapters

Learning objectives

  • Explain semiconservative DNA replication.
  • Describe helicase, primase, polymerase, and ligase functions.
  • Compare continuous leading-strand and discontinuous lagging-strand synthesis.
  • Apply complementary base-pairing rules.
  • Explain how proofreading improves fidelity.

Key concepts

Template copying

Each parental strand guides construction of a complementary new strand.

Antiparallel strands

DNA polymerase extends only from a free 3′ end, so new DNA is synthesized 5′ to 3′.

Two strategies

The leading strand is continuous; the lagging strand uses RNA primers and Okazaki fragments.

High fidelity

Base selection, proofreading, and later repair keep most copied DNA accurate.

Scientific model

The simulation uses a short educational DNA segment. Complementary A–T and G–C pairing, opposite strand orientation, 5′ to 3′ synthesis, primer dependence, fragment joining, and semiconservative products follow established biology. Molecular sizes and timing are visually scaled.

Suggested experiments

  • Lower nucleotide supply and observe slower fork progress.
  • Compare leading and lagging synthesis at the same speed.
  • Reduce proofreading and watch errors persist.
  • Add template damage and test whether the fork pauses.

Common misconceptions

  • Replication does not produce one old and one entirely new molecule.
  • Both new strands are synthesized 5′ to 3′.
  • Helicase separates strands; it does not add DNA nucleotides.
  • RNA primers are temporary starting points, not permanent DNA.
Score: 0 / 7