BIOL 200 Lecture Notes - Lecture 2: Ester, Ribonucleotide, Polymerization
7 Jun 2016
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Document Summary
Using dna template strand: 3" end is the beginning of transcription, proceeds to 5" end. Rna polymerized and synthesized in 5" 3" direction (complimentary) During transcription base paring of ribonucleotides with dna template. Rna polymerases comes along and associated with dna and polymerizes diester bonds between incoming bases to create polymer of rntps. Dna double helix locally denatures and one strand acts as a template: has to be denatured to allow access to active site. Incoming ribonucleotides triphosphates (rntaps)base-pair with bases in the template dna strand. Rna polymerase sequentially joins the rntps from 5" to 3" rna strand growth. Polymerization is energetically favoured because the high energy bond between the alpha and beta phosphates is replaced by a lower energy phosphodiester bond. Conventions for describing rna transcription: double stranded duplex dna. 5" 3" and 3" 5": +1 is start of transcription (there is no zero, everything downstream are the coding sequences.
