How does Taq polymerase facilitate DNA replication during PCR?

Taq polymerase plays a crucial role in the polymerase chain reaction (PCR) by synthesizing new DNA strands. This enzyme is a thermostable DNA polymerase, derived from the bacterium Thermus aquaticus, which allows it to function effectively at the high temperatures used during PCR.

During the PCR process, the DNA being amplified is first denatured, separating the two strands. Once the temperature is lowered for annealing, Taq polymerase facilitates the synthesis of new DNA strands by adding nucleotides complementary to the template strands. It does this by extending from the primers that anneal to the single-stranded DNA, effectively allowing for the replication of the target DNA region. This ability to synthesize DNA at temperatures that would denature most other enzymes is what makes Taq polymerase particularly valuable for PCR, as it survives the high-temperature denaturation step and continues to function in subsequent cycles of the reaction.