1. Unwinding and Separating:
- The double helix of DNA unwinds and separates into two single strands. This is done by an enzyme called helicase.
2. Building a New Strand:
- Each original strand serves as a template for building a new complementary strand.
- An enzyme called DNA polymerase reads the template strand and adds nucleotides (building blocks of DNA) one by one, following the base pairing rules (A with T, and C with G).
3. Proofreading and Repair:
- DNA polymerase has a "proofreading" function, checking for errors and correcting them. Other repair mechanisms also operate to maintain the accuracy of the copy.
4. Joining the New Strands:
- Once the new strands are built, they are joined to the original strands, forming two complete DNA molecules. An enzyme called ligase seals the gaps between the newly synthesized fragments.
Result:
- Each new DNA molecule consists of one original strand and one newly synthesized strand. This is called semi-conservative replication because half of the original molecule is conserved in each new molecule.
Why is DNA replication important?
- It allows cells to divide and create new cells with identical genetic information.
- It ensures the accurate transmission of genetic information from one generation to the next.
