A Brief Explanation of an Over-the-Counter Market | Definition. A over-the-counter market (OTC) refers to a decentralized and informal way of exchanging stocks, derivatives, or other assets between two parties.
The leading strand is built by using the lagging strand of the old molecule as the template. Replication of the leading strand begins with the enzyme âprimaseâ. Primase adds a small complementary piece of RNA (~10 nucleotides), called an âRNA primerâ, near the end of the lagging strand. The RNA primer gives an enzyme called âDNA polymerase IIIâ something to attach a DNA nucleotide to. A jury-rigged design, RNA primers are necessary because DNA polymerase III can only attach nucleotides to the 3â end of a pre-existing nucleotide.
Primase synthesizes the RNA primer that is used to start an Okazaki fragment on the lagging strand. DNA polymerase III continues to add nucleotides to the leading strand right at the replication fork. DNA polymerase I (not at the replication fork) replaces the RNA primers with DNA nucleotides. DNA ligase, also not at the replication fork fuses the new nucleotides produced by polymerase I with the adjacent strand. Replication continues until there are two completely seperate DNA strands that are identical.