transcription (genetic)
Last reviewed 01/2018
This process is outlined below:
- the DNA has a promoter sequence which is 'upstream' of a particular gene. DNA is 'read' in a 5' to 3' direction.
- RNA polymerase recognises the promoter sequence and binds onto the DNA. The RNA polymerase starts transcribing a copy of the DNA sequence (which functions as a template) and produces a single-stranded RNA molecule. The RNA polymerase stops transcribing DNA when it reaches the end of the gene. The RNA molecule formed is messenger (m)RNA. RNA is similar to DNA except that it is single-stranded, contains ribose instead of deoxyribose, and contains uracil instead of thymidine (the bases in RNA are: purines - adenine and uracil; pyrimidines - guanine and cytosine)
- mRNA is processed (splicing out the non-coding regions and modifying each end) and migrates to the cytoplasm where it is used for the synthesis of a specific protein via TRANSLATION.