Which enzyme links together the growing chain of RNA nucleotides during transcription?

RNA polymerase is the key enzyme responsible for synthesizing RNA from a DNA template during the process of transcription. This enzyme facilitates the addition of ribonucleotides to the growing RNA chain, linking them together through phosphodiester bonds. RNA polymerase reads the DNA sequence and catalyzes the formation of the RNA strand in a complementary manner, ensuring that the correct nucleotides are incorporated according to the sequence of the DNA.

In contrast, DNA polymerase is involved in DNA replication, where it synthesizes a new strand of DNA by adding deoxyribonucleotides to a growing DNA chain. RNA ligase and DNA ligase, on the other hand, are enzymes that play roles in joining nucleotides; RNA ligase connects RNA strands, typically in processes requiring the formation of mature mRNA molecules, while DNA ligase connects Okazaki fragments during DNA replication. While all these enzymes are important in nucleic acid metabolism, it is specifically RNA polymerase that performs the pivotal function of linking RNA nucleotides during transcription.