Final answer:
DNA synthesis requires the addition of nucleotides to the 3' end of an RNA primer, with enzymes like DNA polymerase and ligase playing crucial roles in the replication process.
Step-by-step explanation:
The chemistry of DNA synthesis requires the extension of the new DNA chain by adding nucleotides to the 3' end of the primer. DNA replication involves a complex series of events where enzymes, including DNA polymerases and primases, work together to create a new copy of the DNA molecule. DNA polymerase can only add new nucleotides to the 3'-OH group at the end of the primer, which is essential for the growth of the DNA strand.
The leading strand is synthesized continuously from a single primer, while the lagging strand is synthesized in short segments, known as Okazaki fragments, each requiring a new RNA primer. As DNA polymerase III adds complementary nucleotides, the RNA primers are eventually removed and replaced with DNA nucleotides. The gaps left behind are filled, and the nicks are sealed by the enzyme DNA ligase, forming a continuous DNA strand. This process is critical for accurate DNA replication.