In: Biology
1. Describe how gene expression is regulated at every level of the Central Dogma.
Ans)
The whole central dogma is the fornation of mRNA and proteins from transcription and translation processes, respectively.
Regulation of transcription thus controls when transcription occurs and how much RNA is created. Transcription of a gene by RNA polymerase can be regulated by several mechanisms. Activators enhance the interaction between RNA polymerase and a particular promoter which encourgaes the expression of the gene. Silencers are region of DNA sequences which when bound by particular transcription factors which can silence the expression of gene.
The translation of mRNA can be controlled by various mechanisms, mostly at the level of initiation. A large number of RNA binding protein exist in prokaryotes and eukaryotes, which are often directed to the target sequence by the secondary structure of the transcript which may change depending on conditions such as temperature and presence of aptamer. Some transcripts behave like ribozyme and regulate their expression by their own self.