Transcription Flashcards
Template Strand
the strand that is being transcribed
binds to the mRNA as it’s being synthesized
Coding Strand
nontemplate strand
has the same code that the mRNA will have, but doesn’t bind to the mRNA
Initiation
first step of transcription
sigma factor guides the RNA polymerase binding to specific sequences, and facilitates unwinding of the DNA strand (no energy needed)
closed promoter complex, then open promoter complex with unwinding of DNA, synthesis of 5-10 phosphodiester practice bonds, then release of sigma factor once the RNA begins to form
Elongation
for each nucleotide added, base pairing occurs and then a phosphodiester bond forms
Termination
rho-independent: GC rich stem-loop followed by a run of Uracils; the loop rips the weak AU bonds apart when it exits
rho-dependent: pause sites become termination sites in the presence of protein factor rho (a type of helicase that uses ATP)
Promoter Melting
TBP binds to minor groove of DNA molecule, causes sharp bend making it easier to unwind/melt the DNA
Closed Complex
complex of the RNA polymerase bound to a promoter, in which the DNA is intact and double-stranded
Open Complex
A complex of the RNA polymerase bound to a promoter, in which the bound DNA is partially unwound. Transcription initiation occurs in the open complex
Abortive Initiation
early process of transcription in which RNA pol binds to promoter and enters into cycles of synthesis of short mRNA transcripts which are released before the transcription complex leaves the promoter
Promoter Escape
last stage of transcription initiation when RNA pol begins to relinquish hold on promoter and advance downstream on the template
Nascent RNA
primary RNA which needs to be processed to become
Downstream
after the gene site, based on the direction that DNA Pol II is traveling in
rRNA
ribosomal RNA
molecular component of a ribosome, which assembles polypeptides
tRNA
transfer RNA
small RNA molecules that carry AAs to ribosome for polymerization into a polypeptide
