1. Unwinding and Separation:
* The double helix structure of DNA unwinds, and the two strands separate. This is achieved by enzymes called helicases.
2. Template Formation:
* Each separated strand now acts as a template for creating a new complementary strand.
3. Primer Binding:
* Short pieces of RNA called primers bind to the template strands. These primers provide a starting point for the synthesis of new DNA strands.
4. DNA Polymerase Action:
* The enzyme DNA polymerase moves along the template strand and adds new nucleotides, following the base pairing rules (A with T, and G with C).
5. Leading and Lagging Strands:
* DNA replication happens continuously on one strand (leading strand) while the other strand (lagging strand) is synthesized in short fragments called Okazaki fragments.
6. Joining Fragments:
* An enzyme called ligase connects these Okazaki fragments into a continuous strand.
7. Proofreading:
* DNA polymerase has a built-in proofreading function that checks for errors and corrects them as it adds nucleotides.
The Result:
* Two identical DNA molecules are produced from the original DNA molecule. Each new DNA molecule has one original strand and one newly synthesized strand. This process ensures that each daughter cell receives a complete and accurate copy of the genetic information.
Types of Cell Division:
* Mitosis: This type of cell division produces two identical daughter cells, each with the same amount of DNA as the parent cell. This is essential for growth and repair.
* Meiosis: This type of cell division produces four daughter cells, each with half the amount of DNA as the parent cell. This is essential for sexual reproduction.
In summary, DNA replication is a vital process that ensures accurate transmission of genetic information during cell division. It is a highly complex and precisely regulated process that maintains the integrity of the genome.
