Transcription

Question 1

Define the process of transcription

Answer 1

Its the process by which the genetic code of the
DNA is copied on a MRNA. This takes place on the nucleus.

Question 2

Explain the role of the promoter in transcription.

Answer 2

The promoter is a sequence of bases on the DNA near the gene to be transcribed. It is the place where the enzyme RNA polymerase attaches to begin the process of transcription.
This sequence is considered one of the NON-coding DNA sequences; meaning that these sequences will never be translated into a polypeptide.
There are transcription factors that can bind to the promotor to either allow RNA polymerase to transcribe the gene, or suppress the transcription of the gene by preventing RNA polymerase from attaching to the promotor.

Question 3

Outline the process of transcription

Answer 3

1. Initiation: The enzyme RNA polymerase attaches to the promoter region near the gene to be transcribed. It will unwind and un-zip the double DNA helix by breaking the hydrogen bonds between
2. Elongation : Free RNA Nucleoside tri-phosphates which are in the nuclear fluid will be attached to each other by covalent bonds catalyzed by the enzyme RNA polymerase complementary to the base on the DNA template. [ Uracil will form 2 hydrogen bonds with Adenine]. The energy from the bonds the triphosphates will help this attachment.
3. Termination When transcription reaches a special region on the DNA- terminator region- transcr will stop. A fully transcribed RNA molecule is ready to leave the nucleus. This single strand RNA is called a mRNA because it acts as a messenger, carrying the genetic code from the DNA to the ribosomes.
   > This mRNA has yet to be modified before it leavestheNucleus.