Flashcards in EC L2b Deck (13)
RNA processing is also known as...?
post transcriptional modification
what is primary transcript made by?
when is primary transcript made?
when RNA polymerase has finished the job
primary transcript has to be made into what...?
what is RNA processing...?
everything that happens in the process between primary transcript and mature RNA
processing rRNA and tRNA involves what?
cleavage and trimming
which type RNA does NOT get processed?
processing of mRNA- only talking about eukaryotic here as bacteria mRNA is not processed
which (') end is capped and tailing during processing of mRNA
3' is tailing
This might (or might not) be a protective device against nucleases (eukaryotic mRNAs are typically longer-lived than bacterial mRNAs) but, more importantly, the cap is recognised by specific proteins that enable ribosomes to bind to the mRNA and initiate protein synthesis.
Tailing. By far the majority of eukaryotic mRNAs (but not all of them) acquire tails.
Describe the tail It’s a strand of A resedue (polyA tail n-200), when mRNA is first made, it has a long tail, it get shorter with usage and when it ends up with 10 nucleotides in length it gets degraded.
Splicing. This involves the processing of mRNA primary transcripts.
Mature eukaryotic mRNAs are typically much shorter than the genes from which they are transcribed, but the primary transcripts are not.