Describe the physical structure of RNA
Each of the nucleotide "building blocks" is connected to the next by a
3'--> 5' phosphodiester bond.
RNA molecules communicate with proteins through
through the 2'-OH group on the ribose residue. This is an important donor and acceptor of protons.
DNA-dependant RNA polymerase has what type of potential?
highly-proccessive and proof reading potential
mRNA is what % of cells RNA
tRNA is what % of cells RNA
mRNA and hnRNA are synthesized by
RNA polymerase II from DNA
tRNA is synthesized from
primary transcript by RNA polymerase III
tRNA is generally small or large in size?
tRNA is protected from nuclease destruction by
what are some physical characteristic of tRNA?
lots of 2'and 3' structure (prolongs t1/2)
rRNA is synthesized in
Nucleolus by RNA mostly by Polymerase I, however rRNA 5S is synthesized by RNA Polymerase III
two roles of rRNA are
rRNA contributes what % of cells RNA
list some characteristics of rRNA
stable and long lived
considerable 2' and 3' structure
Processing of Eukaryotic rRNA occurs
in the nucleus
The functional ribosome is made of
4 rRNA and 82 Proteins
miRNA is synthesized by
RNA Polymerase II which makes pre-miRNA which is then modified to make miRNA
Major role of miRNA is to
regulate gene expression
synthesis of what types of RNA occur in the nucleoplasm
where does rRNA synthesis occur
process of transcription in the 5' -->3' direction start at specific DNA sequences called
The new RNA is transcribed in what direction
Does RNA Polymerase require a primer
In prokaryotes the enzyme that catalyzes transcription contains
4 subunits 2 Alpha, Beta, Beta' (the core enzyme) and a sigma factor
what is the role of the sigma factor in prokaryotes
initiation of transcription which may be dissociated upon completion.
It reduces the affinity of the Polymerase for peripheral DNA, allowing to bind to promoter
Prokaryotic RNA polymerase can be inhibited by
semisynthetic antibiotic rifampicin
semisynthetic antibiotic rifampicin is an effective treatment of
polio caused by Mycobacterium tuberculosis
what is the role of Actinomycin D
prevents formation of the replication bubble.
The smaller 40S subunit, is composed of
a single 18S rRNA and 33 proteins
the larger subunit contains
28S, 5.8S and 5S rRNA plus 49 proteins
what can help catalyze the formation of the peptide bonds between amino acids in protein synthesis.
transcription is catalyzed by
RNA polymerase I
what is special about 5S RNA
transcribed and processed independently in the nucleus by RNA polymerase III.
Does RNA synthesis require a Primer?
The body has two natural methods to close the replication bubble. they are
GC--AT PolyU Tail/Hairpin structure
Hexameric rho protein
A method that do not naturally occur to stop the replication bubble are