BIOC 2580 Study Guide - Final Guide: Apolipoprotein B, Transfer Rna, Africa Movie Academy Awards
16 Dec 2015
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Document Summary
Because eukaryotic transcription and translation are spatially separated, rna is processed before it is an mrna to be sent out to the cytoplasm. Capping occurs during transcription by a capping enzyme that is attached to the rnapii. When rna strand is about 25-30 nt long, methylated cap is added to the 5" end. After transcription, capped pre-mrna can be released from the. At the cap, there is a triphosphate linker to guanine cap as opposed to the single phosphate that typically exists between bases. Guanylyl transferase catalyzes the addition of the guanylyl residue from gtp. If the cap only has a single methyl group on the guanyl, it is capo (occurs in all eukaryotic mrnas) If a methyl is also added to the 2" o position of the first nucleotide, it is considered cap 1 (predominant cap form in all multicellular eukaryotes) Rnap transcribes past the poly(a) consensus sequence originally, resulting in the 3" utr.
