DNA replication is a crucial process that occurs in all living cells, ensuring that genetic information is accurately copied and passed on during cell division. Here’s the correct order of the steps involved in DNA replication:
- Initiation: The replication process begins at specific locations in the DNA, known as origins of replication. Enzymes called helicases unwind the double helix structure, separating the two strands of DNA.
- Priming: RNA primers are synthesized by the enzyme primase. These primers provide a starting point for DNA synthesis by providing a free 3′ hydroxyl group for DNA polymerase to add nucleotides.
- Elongation: DNA polymerase adds complementary nucleotides to the growing strand of DNA, starting from the RNA primer. This process occurs in both directions as the two strands of DNA are antiparallel, resulting in the leading strand being synthesized continuously while the lagging strand is created in short Okazaki fragments.
- Replacement of RNA Primers: After the DNA strands have been elongated, the RNA primers are removed and replaced with DNA nucleotides. This is carried out by another form of DNA polymerase.
- Ligation: Finally, the enzyme DNA ligase seals the gaps between the Okazaki fragments on the lagging strand, creating a continuous strand of DNA, completing the replication process.
This ordered process ensures that the genetic material is accurately copied, maintaining the integrity of the organism’s genome.