What is the process of DNA replication?

The process of DNA replication occurs in three major steps: the unwinding of the double helix and separation of DNA strands, the priming of the template strand, and the assembly of a new DNA strand. The two strands of DNA uncoil at the site called the origin. The initiation of DNA replication has two steps involved. First, an inhibitor protein unwinds a short portion of the double helix. Then, helicase attaches and breaks the hydrogen bonds of the nucleotide bases on DNA strands, separating them. Helicase proceeds to break hydrogen bonds and separates the polynucleotide chain. Simultaneously, primase also attaches to each strand and creates a starting point where replication can begin, known as a primer.   

Once the primer is attached on a single, unwound polynucleotide strand, DNA polymerase wraps around that same strand and attaches new nucleotides to the nitrogenous bases. Thus, the polymerase creates a new complementary DNA strand on top of the original one. Complementary base pairing then takes place as DNA polymerase works its way down the unwound DNA strand. A and T and C and G nucleotides always pair with one another due to their molecular structures. This is also known as elongation, which results in the completion of 2 complementary DNA strands. Base pairing is important because later when the new strand is copied, its complementary strand will contain the exact sequence as the original template strand. RNA polymerase continues to transcribe until there are signals to stop. This process is known as termination, which occurs once the RNA polymerase transcribes a terminator sequence. On a side note, prokaryotic E coli replicates at 1,000 nucleotides per second, while eukaryotic human DNA replicates at 50 nucleotides per second.