Transcribe The Information Off Of The DNA Strand Into Messenger RNA For Translation

The purpose of transcription is to transcribe the information off of the DNA strand into messenger RNA for translation. There are three stages that take place in transcription; initiation, elongation, and termination. The first stage is initiation, which starts the whole process. During initiation the enzyme RNA polymerase binds to the promoter, which signals the starting point of transcription. When the RNA polymerase binds to the promoter the DNA strands unwind and transition from double-strands into single-strands. In the next step, elongation, the RNA polymerase adds nucleotides to the 3’ end of the growing RNA chain as it moves down the strand. While this is happening the new RNA molecules that have just been made come off of the DNA template and the previous

This simultaneous transcribing can help the cell make larger amounts of the encoded proteins by increasing the amount of mRNA that is transcribed. The growing RNA strands are like tails coming off of each RNA polymerase that represent how far the enzyme has traveled from the starting point. The next step is termination, which is basically the ending of transcription. The process of termination varies between bacteria and eukaryotes. In bacteria, transcription will get to a terminator sequence also known as a termination signal. This will signal the RNA polymerase to detach from the single DNA strand. In eukaryotes, the RNA polymerase II reaches a sequence of six nucleotides which is called the polyadenylation signal sequence (AAUAAA) and is bound right away by proteins in the nucleus. Later on down the strand the proteins from the nucleus cut off of the RNA polymerase and releases the pre-mRNA. The cleavage marks the end of the mRNA, but the RNA polymerase continues to transcribe until the enzymes meet up with it and it disconnects from the DNA