Molecular (Kaplan) 2 Flashcards
What does RNA pol I do in eukaryotic cells? Where is it located?
Produces all ribosomal subunits, EXCEPT for the 5S subunit. Nucleolus.
What does RNA pol II do?
hnRNA/mRNA and some snRNA
RNA pol III?
tRNA and 5S ribosomal subunit
What must bind to the promoter before RNA polymerase to begin transcription in prokaryotes? In eukaryotes?
σ; transcription factors
What factor is sometimes required to terminate transcription in prokaryotes? In eukaryotes?
ρ; unknown
What drug is used to prophylax against meningitis in close contacts of a pt?
Rifampin
What is the other main use of rifampin?
TB
Mech of rifampin?
Inhibits prokaryotic RNA polymerase
What toxin inhibits eukaryotic mRNA synthesis? What RNA pol does it inhibit then?
α-amanatin of the death cap mushroom inhibits RNA pol II.
What post-translational modification is made to the 5’ end of hnRNA to make it mRNA?
7-methylguanosine 5’ cap
What post-translational modification is made to the 3’ end for mRNA?
poly-A tail
What sequence indicates the site for addition of the poly-A tail?
AAUAAA
What is the Shine-Dalgarno sequence?
It is the site on prokaryotic mRNA that indicates the ribosomal binding site.
What are the two special sequences on the promoter region of eukaryotic DNA at -70 and -25 bases, respectively?
CAAT box and TATA box
What is the size of the eukaryotic ribosome? Each subunit?
80S composed of 60S and 40S
