MICRB 201 Study Guide - Midterm Guide: Titer, Ames Test, Symporter
Document Summary
Process of converting structural genes into rna transcripts: could be mrna, trna, rrna, srna, etc. Features: moves in same direction as dna polymerases (5" to 3") relative to rna synthesis, one of the subunits, sigma factor identifies the promoters (start of genes) Not always associated with rna pol; only necessary at initiation (dissociates during elongation) *antibiotics can bind to rnap and inhibit transcription: transcription stops after recognition of terminator sequence at 3" end gene. Mrna transcripts may be mono- or polycistronic, like trna and rrna genes: however, polycistronic mrnas are not processed : each gene has its own ribosome binding site. 3 major rna polymerases in eukaryotes: rna pol 1 makes rrna, rna pol 2 makes mrna, rna pol 3 makes trna. Instead of sigma factors, eukaryotes use transcription factors. Eukaryotic trna and rrna and mrna: arise by post-transcriptional processing: prokaryotic mrnas do not get processed.
