Replication of DNA is considered to be unique because of it’s ability to duplicate itself. The replication of DNA occurs before cell division. The following is a compendium of how DNA replicates.
Helicase initiates the unzipping of the DNA, which breaks the weak hydrogen bonds that pair the bases together.
The helicase, starting at a certain region of the DNA, unzips the DNA in opposite directions. The point in which the DNA strands is termed as the replication fork.
As the helicase continues to unzip the DNA molecule into two strands, new DNA strands, with the same bases and nucleotides, readily join and pair up with the unzipped DNA strand.
Result: Two DNA Molecules, each with one new strand of DNA and an old strand of DNA, which is called semi-conservative.
The new strand of DNA just can’t appear, so where does it come from?
Primase uses three RNA nucleotides in placement of the DNA nucleotides, to being the new strand.
DNA polymerase, which requires three nucleotides to begin it’s function, adds to the RNA nucleotides creating short segments of DNA, which is called Okzaki fragments.
The Okzaki fragments are joined together by an enzyme, called ligase, and then the newly replicated DNA strand is base paired with the opposite old DNA strand.
Best viewed in a maximized window and with a monitor resolution of 1024 x 768. All written materials and information
were fully composed, as well as altered images and diagrams, by Josh Eisma (2002), unless otherwise specified.
