Which enzyme is responsible for synthesizing the RNA strand during transcription?

During transcription, the enzyme that synthesizes the RNA strand is RNA polymerase. This enzyme plays a crucial role in catalyzing the formation of RNA from a DNA template. It binds to the promoter region of the DNA, unwinds the double helix, and synthesizes a complementary RNA strand by adding ribonucleotides that are complementary to the DNA template strand. This process is key for gene expression, as the RNA produced can be used for protein synthesis or can function in various regulatory roles within the cell. RNA polymerase is essential for transcribing mRNA, tRNA, and rRNA, which are vital components in translating genetic information into functional proteins.