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Principles of controlling gene expressoin. For transcription to begin the gene needs to be stimulated by transciptional factors. These move from the cytoplasm into the nucleus. Each transcriptional factor has a site that binds to a specific region of DNA
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Principles of controlling gene expressoin • For transcription to begin the gene needs to be stimulated by transciptional factors. These move from the cytoplasm into the nucleus. • Each transcriptional factor has a site that binds to a specific region of DNA • When it binds it stimulates transcription • mRNA is then produced and translation into a polypeptide occurs. • When the gene is not being expressed the site that the transcriptional factor binds to is blocked by an inhibitor molecule. • The inhibitor molecule prevents the transcriptional factors from binding and thus prevents transcription
Regulation of transcription and translation • One way which has been researched but you do not have to necessarily know about is the LacOperon
Regulation of transcription and translation • The example you have to know about is how the effect oestrogen has on transcription. • Using figure 1 from page 214 and the information on page 240 produce a flow diagram of how oestrogen effect gene transcription.
The effect of siRNA on gene expression • http://www.nature.com/focus/rnai/animations/index.html • Watch the following animation and make notes, we are going to watch it twice so do not panic! • Read through the two articles about how Andrew Z. Fire and Craig C. Mello were award the Nobel prize for their work in discovering si-RNA • Task using you notes and the articles write a 5 minute speech explaining what si-RNA is, how it works and its significance to medicine.
Question time! • Complete the application questions from page 242 – 243 • Start working on the exam style questions on page 244 – 245 these have to be completed for homework.