Question

Taq polymerase is a heat stable DNA polymerase from Thermus aquaticus.

1) a reverse transcriptase
2) an RNA polymerase
3) from E. coli
4) an RNA polymerase AND from E. coli

Answer 1

Taq polymerase is a heat-stable DNA polymerase crucial for PCR, isolated from Thermus aquaticus, not E. coli, and it does not function as an RNA polymerase.

Step-by-step explanation:

Understanding Taq Polymerase

Taq polymerase is a heat-stable DNA polymerase isolated from the thermophilic bacterium Thermus aquaticus. This particular polymerase is a key component in the polymerase chain reaction (PCR) as it remains functional at high temperatures, which is necessary to denature DNA strands during the amplification process. Being thermostable, Taq polymerase does not require replenishment after each cycle of heating and cooling, making it ideal for PCR where repetitive thermal cycles are used to synthesize multiple copies of a specific DNA segment.

Thermus aquaticus thrives in the extreme environment of the hot springs in Yellowstone National Park, which is much different from the commonly studied Escherichia coli (E. coli), and hence, Taq polymerase is not derived from E. coli nor does it function as an RNA polymerase. In reverse transcriptase PCR (RT-PCR), cDNA is synthesized from an RNA template before PCR, but this process utilizes a different enzyme known as reverse transcriptase, not Taq polymerase.