DNA replication: copying 3 billion letters without typos
Process map by Brian. 23 steps, 3 layers. Tags: science, biology, genetics.
- The cell: A signal says: time to divide
- Helicase (the unzipper): Helicase unzips the double helix at the origin
- The DNA: The replication fork opens
- Primase: Primase lays down short RNA primers
- DNA polymerase (the builder): Polymerase builds the new strands
- DNA polymerase (the builder): Proofreading: was that the right base?
- Ligase (the stitcher): Ligase stitches the fragments together
- The cell: Mismatch-repair crew does a final scan
- The cell: Is the copy perfect?
- The DNA: Two identical DNA molecules, ready for two new cells
- The cell: Repair enzymes cut out and fix the error
- DNA polymerase (the builder): Back up, snip out the wrong base and replace it