Elongatio Initiation Stage 3 Stages Of Transcription

Transcription is the first stage of gene expression and occurs in the nucleus. The purpose of transcription is to synthesize pre-messenger RNA (mRNA) and make it into mature mRNA by using the information found in DNA. The more basic way of explaining it is to rewrite DNA into RNA. This process involves DNA, specifically promoter, coding and termination sequences. It also uses the enzyme, RNA polymerase, a protein complex that reads the DNA template and make RNA. The goal of transcription is to make messenger RNA or proteins. There are three stages of transcription: Stage One is Initiation, Stage Two is Elongation, Stage Three is Termination. The first stage is Initiation. This stage happens when the transcription initiation complex and the RNA polymerase finds a DNA molecule, where the DNA is unzipped to be transcribed. Then the RNA polymerase finds a promoter site and binds to it in in the DNA creating a closed area. The promoter has an initiation site where the process begins, polymerase then synthesizes a complementary RNA strand from a DNA strand and moves the coding sequence so that the gene can be transcribed.

After transcription is initiated this stage starts with a DNA template and transcribes it to RNA. Instead of having thymine like DNA, RNA has uracil. So the RNA polymerase synthesizes from 5’ to 3’ . Free RNA the connects with the complementary base DNA, making the template DNA split to form mRNA. When the the new DNA is rewritten it then goes back to form a double helix. The new RNA strand does not attach to the DNA strand, it goes to the side and progressively gets longer as the process continues until it reaches the terminator