In prokaryotes, three main types of polymerases are known: DNA pol I, DNA pol II, and DNA pol III. ... An enzyme called helicase unwinds the DNA by breaking the hydrogen bonds between the nitrogenous base pairs. ATP hydrolysis is required for this process.

Does RNA polymerase require ATP?

RNAP accomplishes de novo synthesis. ... Such specific interactions explain why RNAP prefers to start transcripts with ATP (followed by GTP, UTP, and then CTP). In contrast to DNA polymerase, RNAP includes helicase activity, therefore no separate enzyme is needed to unwind DNA.

Does DNA polymerase require energy?

The process uses a complementary, single strand of DNA as a template. ... The energy required to drive the reaction comes from cutting high energy phosphate bonds on the nucleotide-triphosphate's used as the source of the nucleotides needed in the reaction.