The PCR (polymerase chain reaction) protocol that is currently used in laboratories was facilitated by the discovery of a bacterium called Thermus aquaticus in a hot spring inside Yellowstone National Park, in Wyoming. This organism contains a heat-stable form of DNA polymerase known as Taq polymerase, which continues to function even after it has been heated to 95°C. Why would such a heat-stable polymerase be beneficial in PCR?
◦ Each cycle includes a "hot" denaturation phase (95°C), which serves to sterilize the culture.
◦ Each cycle includes a "hot" denaturation phase (95°C), which activates the Taq polymerase.
◦ Each cycle includes a "hot" saturation phase (95°C), which allows the primers to anneal to the target DNA.
◦ Each cycle includes a "hot" denaturation phase (95°C), which separates the hydrogen bonds that hold the strands of the template DNA together.
◦ More than one of the above are correct.
Architecture of the replicative DNA polymerase III holoenzyme from E. coli
For this bimolecular reaction, the rate constant k is second order
Reaction at constant-volume
Reaction at constant-pressure
Channel Mediated Facilitated Diffusion
Witting Reaction