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 95ᵒC.Why would such a heat-stable polymerase be beneficial in PCR?
A) Each cycle includes a "hot" saturation phase (95°C), which allows the primers to anneal to the target DNA.
B) Each cycle includes a "hot" denaturation phase (95°C), which serves to sterilize the culture.
C) Each cycle includes a "hot" denaturation phase (95°C), which activates the Taq polymerase.
D) Each cycle includes a "hot" denaturation phase (95°C), which separates the hydrogen bonds that hold the strands of the template DNA together.
E) More than one of the above are correct.

Question

Quizplus · Accepted Answer

The heat-stable Taq polymerase is beneficial in PCR because each cycle includes a "hot" denaturation phase (95°C), which separates the hydrogen bonds that hold the strands of the template DNA together. This allows the Taq polymerase to access and extend the primers along the template DNA. Taq polymerase can withstand the high temperature used for denaturation, making it ideal for the PCR process. Therefore, option D is the correct choice.

The PCR (Polymerase Chain Reaction)protocol That Is Currently Used in Laboratories