The replication of DNA happening during the S phase of Interphase before mitosis happens, and copies itself to be able to start undergoing cell division in the Prophase.
* DNA replication does not increase the chromosome number in the cell. It allows there to be enough DNA information to be split between two daughter cells whilst maintaining the same number of chromosomal sets.*
- The process of copying DNA is called Replication.
- Helicase works first by cutting the DNA bases hydrogen bonds, and the point where the splitting starts is called the hydrogen fork.
- This creates two strands, the top strand and the lagging strand.
- The unwound sections can be used as a base template to create two DNA strands.
- The leading strand has a enzyme called DNA polymerase adding matching nucleotides to the remaining bases.
-Before the DNA polymerase is able to match the new nucleotides, RNA (Ribonucleic Acid) primase acts like a primer to help the DNA polymerase to attach (and is only needed at the start of the strand).
- DNA polymerase can only attach new bases to stands that run in the carbon formation of 5'-3' prime direction. The Lagging strand runs in the opposite direction at 3'-5' prime.
- This mean the lagging strand has to be replicated sections at a time, so the RNA primase primes small part of the strand to allow the DNA polymerase to go backwards along the stand.
- These segments are about 1000 to 2000 bases long starting with the Okazaki fragments, allowing synthesis in small sections.
- The bases all get paired up with a enzyme called DNA Ligases.
- DNA Polymerases re-reads the DNA to remove nucleotides when a mismatched bases is discovered.
*There is 6 feet of DNA in the nucleus of every cell*
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