DNA Replication Process
Ever wonder how your body makes trillions of cells with the exact same DNA? It all happens during the S phase of interphase when your cells copy all their DNA. The original and copied chromosomes become sister chromatids connected at the centromere.
The replication process begins when an enzyme called DNA helicase unwinds and unzips the double helix by breaking hydrogen bonds. This creates a Y-shaped structure called the replication fork where the actual copying occurs. Think of it like unzipping a jacket to access what's inside.
Next, DNA polymerase gets to work assembling new complementary DNA chains using free nucleotides floating in the nucleus. This amazing enzyme not only builds new DNA strands but also proofreads and fixes mistakes along the way! When replication is complete, the two new DNA strands wind up, creating two exact copies of the original DNA.
Quick Tip: Remember that DNA replication happens before cell division—the cell needs to make sure each new cell gets a complete set of instructions!
