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.
Before replication can take place, an enzyme called helicase unwinds the DNA molecule from its tightly woven form, in the process breaking the hydrogen bonds between the nucleotide bases. This opens up or unzips the double-stranded DNA to give two single strands of DNA that can be used as templates for replication.