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Biochemistry 2280A Lecture Notes - Lecture 19: Hemoglobin, Phosphodiester Bond, Primary Transcript

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School
Western University
Department
Biochemistry
Course
Biochemistry 2280A
Professor
Chris Brandl

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Document Summary

Eukaryotic cells: 5" capping, 3" polyadenylation, splicing. 5" capping (fig 7-16: mrna has triphosphate gets replaced by 7"methylguanosine. Importance of the 5" cap and 3" polya tail: mark the 5"and 3" ends of the mrna as being intact, required for mrna export (no point of transporting garbage mrnas to the cytosol to be translated) and translation. If there was only 5" cap, it knows that the 3" part was clipped, so it gets trashed: protect the mrna from degradation. Rna splicing: occuring while transcription is happening, protein encoding sequences (exons) are interrupted by noncoding sequences (introns, gene is interrupted by intron sequences, exons= expressed, introns= interruptions, human factor viii gene has mostly introns. Introns are spliced out of the primary transcript to give the mature mrna. Increases coding capacity of the genome: differential splicing- an rna can be spliced in different ways to create related but distinct protein products, beneficial because it allows differential splicing.

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Related Questions

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