Final answer:
RNA polymerase uses one strand of DNA as a template to synthesize RNA. A primer synthesized by primase is required to start the process, while RNA polymerase elongates the RNA strand by adding nucleotides complementary to the template strand.
Step-by-step explanation:
When RNA polymerase starts the process of transcription, it unwinds the DNA double helix and uses one strand of DNA as a template for synthesizing RNA. This template strand contains the necessary genetic code that informs the sequence of the RNA molecule being produced. RNA polymerase facilitates the alignment of RNA nucleotides which are complementary to the DNA template strand, following the rules of base pairing (adenine with uracil and cytosine with guanine). This process occurs in the nucleus where all necessary enzymes and nucleotides are present for RNA synthesis.
In the initial stage, an enzyme called primase synthesizes a short segment of RNA, often referred to as a primer, which is necessary for DNA synthesis to begin. This primer provides the free 3'-OH end required for DNA polymerase to start adding nucleotides. Subsequently, during the stage of elongation, RNA polymerase continues to build the RNA strand by adding nucleotides one by one, extending from the 3' end of the growing RNA strand.
RNA polymerase binds to specific regions of the DNA called promoters, initiating the transcription process. Once the transcription begins, the coding strand of the DNA, which is the non-template strand, is used as the blueprint to determine the sequence of RNA nucleotides, ensuring that the genetic information is accurately copied into the RNA molecule