Practice question

Taq DNA polymerase exhibits maximal catalytic activity at elevated temperature, reflecting its thermophilic origin. Standard PCR extension is performed at 72°C, matching optimum where polymerase incorporates nucleotides at approximately 60 to 100 bases per second while maintaining duplex stability of newly synthesized strand. Lower temperatures such as 54°C correspond to annealing, and 94°C to denaturation, while 25°C is insufficient for enzymatic activity. Maintaining 72°C allows efficient, processive elongation of full-length amplicons up to several kilobases without enzyme denaturation, supporting robust amplification yields.