DNA replication is the process by which a DNA molecule is duplicated to produce two identical DNA molecules. This occurs during cell division, ensuring each new cell receives a complete set of genetic instructions. The process is highly precise and involves a series of steps:
- Unwinding and Separation: The double-stranded DNA molecule unwinds at a specific location called the origin, forming a Y-shaped structure called a replication fork. This unwinding is facilitated by enzymes like helicases.
- Primer Binding: A short sequence of RNA, called a primer, binds to the unwound DNA strands. This primer provides a starting point for the DNA polymerase enzyme.
- DNA Polymerase Action: DNA polymerase, a specialized enzyme, uses the existing DNA strand as a template to assemble new complementary strands. It reads the original strand and adds nucleotides, forming a new strand that is identical to the original.
- Joining of Fragments: The newly synthesized DNA fragments are joined together by an enzyme called DNA ligase, creating a complete DNA molecule.
The process of DNA replication is semiconservative, meaning each new DNA molecule contains one original strand and one newly synthesized strand. This ensures that the genetic information is accurately passed on from one generation to the next.
