Biology 1002B Lecture Notes - Lecture 15: Start Codon, Release Factor, Transfer Rna
Document Summary
Cycle 6: relative location of such dna sequence signals as promoter, 5" and 3" utr, sd box , start codon, stop codon, transcription terminator etc. 5" and 3" utr are non coding regions that are untranslated in the process of protein synthesis: they flank the coding region of the mrna. At the stop codon there is no trna that base-pairs with the mrna to stop translation. Instead, the ribosome stalls because there is no trna and a release factor protein gets into the site. The protein does not base-pair because proteins don"t have. Promoters attract transcription factor proteins: bind and orient polymerase to begin transcription. 3. less attraction of factors less polymerase binding less transcription. High efficiency promoters: more attraction of factors, more polymerase binding, more transcription. High efficiency promoters: more attraction, more transcription, characteristics of promoters that require a particular position and direction. Promoters are found on sense strand (strand that is transcribed) and are downstream of gene.
