BI110 Lecture Notes - Lecture 9: Spliceosome, Guanosine, Intron
Document Summary
Incoming ribonucleotides are accepted if they correctly base pair w the template dna. The 3"-oh of the growing strand attacks the high-energy phosphate bond of the incoming ribonucleotide, providing the energy to drive the rxn. The 2 phosphates of the incoming ribonucleotide are released as pyrophosphate (dna polymerase works the exact same way) Has proteins which get the nontemplate dna strand out of the way. Has a part to store incoming rna trinucleotides. Primary transcript is the rna transcript that comes off the template dna strand. In prokaryotes, transcription & translation are coupled; translation begins even before transcription is completed. When transcription is finished, primary transcript will not be able to go through translation immediatley. Introns = non coding, therefore must be removed (splicing) Guanosine that has an extra methyl group on the 7 position. Added in a 5"-5" phosphate linkage (3 phosphates) Without the addition of the cap, translation wouldn"t occur. Polyadenation adds poly(a) tail to the 3" end.
