Enzyme used in PCR is
In step 3 i.e polymerization : New DNA strands are synthesized by Taq polymerase. This enzyme is derived from bacteria Thermus acquaticus that are found in hot springs.Therefore the enzyme is not denatured at high temperature. REFERENCE : DM.VASUDEVAN.TEXTBOOK; SEVENTH EDITION; PAGE NO :638.
Reverse transcriptase
Taq polymerase
RNA polymerase
None
Metabolism of nucleic acids