Transcription and RNA Processing Flashcards
Are the genes that encode the non-major types of RNA translated?
no, they’re not translated but the RNA products producing during transcription used for processing of translation
What is the type of eukaryotic RNA polymerase: it is located in the nucleoplasm and synthesizes tRNA, some snRNA, and 5S rRNA?
RNa polymerase III
What are the two types of ways transcription is terminated in prokaryotes?
ρ dependent and ρ independent termination
What is the general type of enzyme that performs transcription?
DNA dependent RNA polymerase
In prokaryotes, the ribosomes bind to what codon in the beginning of translation?
AUG codon
What is the purpose for the addition of the 7-methylguanosine cap on the 5’ end of pre-mRNA in the nucleus?(2 points)
It protects the pre-mRNA from degradation and it serves as the attachment site for the ribosomes
What protein factor is required for α2ββ RNA polymerase to initiate transcription at the promotor?
σ factor
What is the type of RNA polymerase: it is locaed in the nucleolus and synthesizes 28S, 18S, and 5.8S rRNAs?
RNA polymerase I
What is the type of eukaryotic RNA polymerase: it is located in the nucleoplasm and synthesizes hnRNA/mRNA and some snRNA?
RNA polymerase II
Eukaryotic RNA polymerases are inhibited by what drugs?(2 points)
α-amantin(RNA polymerase II) and actinomycin D
What type of prokaryotic termination of transcription: termination occurs when the newly formed RNA foldsback on itself to form a GC-rich hairpin loop closely followd by 6-8 residues.
ρ-independent
What is in the promoter region for RNA polymerase II during transcription of mRNA?(4 points)
Two promoter sequences, TATA box and CAAT box
What is a monocistronic message?
mRNA which codes for one protein
Polyadenylation of pre-mRNA occurs in what suborganelle structure? This is generally associated with active gene expression in what?
Polyadenylation occurs in the nucelplasm. It is generally associated with gene expression in euchromatin.
What is the number system for bases located to the right or downstream from the starting point for transcription?
+2, +3, +4,…
What is a transcription factor for RNA polymerase II, assist in initiating transcription?
TFIID
Does eukaryotic RNA polymerases require σ factor to initiation transcription at the promoter?
No, they do require TFII to bind before RNA polymerase
What is the sequence where an endonuclease cuts the mRNA molecule for the addition of the poly-A tail?
AAUAAA
What type of prokaryotic terrmination: termination requires paricipation of protein factor which binds to the newly formed RNA and moves toward the RNA polymerase that has paused at a termination site; protein then displaces RNA plymerase from the 3’ end of the RNA.
ρ dependent termination
Why are introns not transcribed to mRNA in the nucleus?
Wrong, both introns and exons are transcribed to mRNA in the nucleus
How long does σ factor remain at the promoter during the initiation of transcription?
It is released immediately after the initiation of transcription has taken place
What are the major types of processing of pre-mRNA that occur inside the nucleus of a ekaryotic cell?(3 points)
The addition of a 7-methylguanosine to the 5’ end of the mRNA, the addition of the poly-A tail and the removal of the introns from the pre-mRNA
A major type of RNA which is used as a structural component of the ribosome to form a complete, functional ribosome?
Ribosomal RNA
Ribosome, in prokaryotic translation, synthesized the polypeptide in what direction?
amino terminus to carboxy terminus
If the lactose operon conains three different types of gene as part of its coding sequence, how many Shine-Dalgarno sequences at the utranslated region of the mRNA are going to be in the polycistronic mRNA?
three
How does RNA polymerase proofread its work?
It doesn’t proof its work
When/where are introns removed during mRNA transcription eukaryotes?
they’re removed during RNA processing in the cytoplasm
What part of the tRNA molecule bind to the codon located on mRNA?
the anti-codon region
What is another name for TATA box in eukaryotes?
Hogness box
What is the specific action of the Shiga toxin from Shigella dysenteriae and Verotoxin, shiga-like toxin from enterohemorrhagic E. coli on suborganelle structures?**(2 points) **What are the toxins?
It removes the adenine residues from the 28S rRNA found in the 60S subunit. The toxins are RNA glycosylases.
The RNA product has what properties when compared to the template strand?(2 points)
complementary and anti-parallel
How does RNA polymerase recognize the start and end of a particular sequence of bases which encodes a gene?
promotor and terminator
What type of RNA polymerase in eukaryotes synthesize mRNA from DNA template strand?
RNA polymerase II
What are removed during pre-mRNA processing in eukaryotes: introns or exons?
introns are removed
What is the action of rifampin?
Rifampin inhibits prokaryotic RNA polymerase
What is the coding segment of mRNA in eukaryotes: introns or exons?
exons
How many type of activated amino acids do tRNa molecules carry during translation?
They carry only ONE
What is the second most abundant type of RNA in the cell?
tRNA
The fist stage in the expression of genetic information is a particular processing of the information to the base sequence of a double-stranded DNA molecule to form the the base sequence of a single-stranded molecule of RNA.
Transcription
A major type of RNA which are RNA molecules with enzymatic activity?
ribozyme
How does helicase and RNA polymerase work together to seperate the template strand from the coding stand in eukaryotic transcription of mRNA?
RNA polymerase II doesn’t work with helicase. RNA polymerase seperates the strands in a short distance and transcribes the mRNA from the 5’ to the 3’ location and it reads the template strand from the 3’ to the 5’ direction.
When/where are exons are removed in eukaryotes after transcription has taken place?
they’re not removed
During transcription, does RNA polymerase move in the 5’ - 3’ direction or the 3’ to 5’ direction?
It moves in the 3’ - 5’ direction but it synthesizes from 5’ to 3’
What are the three basic steps of eukaryotic ribosome synthesis starting from the nucleus?
The eukaryotic rRNA is transcribed by RNA polymerase I in the nucleuolus as one large peice: 45S. The 45S is later broken down into 28S, 5.8S and 18S. RNA polymerase II transcribes the 5S region from a seperate gene. All of the rNA assemble in the nucleolus with ribosomal proteins.
What is the purpsoe for the poly-A tail addition to the 3’ end of the pre-mRNA molecule in eukaryotic processing of mRNA?
Protects the pre-mRNA from degradation from nucleases and it aids it transport to the cytoplasm
All transcription can be inhibited by what drug?
antinomycin D
What portion of the tRNA molecule is phosphorylated?
The 5’ end
What type of primer is required for transcription?
None
What is the rRNA that make up the 30S subunit?
16S RNA
A major type of RNA that is found only in the nucleus of eukaryotes but one of its major function is to participate int he splicing of eukaryotes?
small nuclear RNA
What specific sequences are required at hte promoter location for prokaryotic transcrition?(4 points)
2 promoter sequences, a “TATA” box and a -35 sequence
The ρ-independent termination mechanism in prokaryotic transcription has a base sequence rich in what specific type of nucleotides?(2 points)
Guanine/Cytosine base pairing mechanism
When does translation start in prokaryotes?
Translation and transcription occur at the same time in prokaryotes
What is the most abundant type of RNA in the cell?
ribosomal RNA
What is the coding seqeunce of the acceptor arm that careries the amino acid in a tRNA molecule?
5’-CCA-3’
What is a polycistronic message?
mRNA which codes for multiple proteins
What is the purpose of the poly-A tail in eukaryotic processing of pre-mRNA?(2 points)
protects the mRNA from degradation and transportation to the cytoplasm
What is the single prokaryotic RNA polymerase that synthesizes all types of RNA in the cell?
α2ββ’
How are the introns removed and exons assembled in pre-mRNA processing in eukaryotes?(3 points)
Introns are removed by splicosomes, i.e., snRNP, from the 5’(donor) to the 3’(acceptor) ends of the intron. The introns are removed. The intron is excised in the form of a lariat structure and later degraded. The neighboring exons are joined together to join the coding region of mRNA.
What are the major roles of RNA in the cell?(6 points)
tRNA, ribosomal RNA, messenger RNA, heterogenerous nuclear RNA, small nuclear RNA and ribozymes
What is the rRNA that make up the 60S subunit?(3 points)
5S, 5.8S and 28S rRNA
Where does RNA polymerase bind to begin transcription?
promoter region
What are the two subunits of rRNA that make up the eukaryotic ribosome?
40S and 60S
Where do the ribosomes bind on the prokaryotic mRNA to initiate translation?
Shine Dalgarno region on the untranslated region of the mRNA. This is the 5’ region of the UTR region.
All of the intermediate pre-mRNA structures in the pre-mRNA procesing which occurs in eukaryotes, are referred to as what?
hnRNA or heterogenous nucleus RNA
What type of introns are found in prokaryotes?
none
In prokaryotes, how does helicase work together with RNA polymerase to seperate the template strand from the non-template(coding) strand?
RNA polymerase the two strands as it reads the base sequence of the templerate strand
What is the action of actinomycin D?
It binds to the DNA and preventing transcription
What is the rRNA that make up the 50S subunit?(2 points)
5S and 23S
When does transcription end?
When RNA reaches a termination signal
What specitic type of sequences are found in the termination signal are found during eukaryotic transcription?
It is a terminal signal that isn’t well understood
A major type of RNA which carries the information specifying the amino acid sequence of a protein to the ribosome?
Messenger RNA
What type of RNA polymerase in eukaryotes synthesize the eukaryotic ribosome?(2 points)
RNA polymerase I and RNA polymerase II. RNA polymerase I synthesizes a large portion of the rRNA that makes up the ribosome
What is the number system for bases locatd to the left or upstream from the starting point for transcription?
-1,-2,-3,…
A major type of RNA that is found only in the nucleus of eukaryotic cells?
heterogeneous nuclear RNA
What is the rNA that make up the 40S subunit?
18S rRNA
What RNA polymerase transcribes tRNA in eukaryotes?
RNA polymerase III
What is an example of mRNA that doesn’t have a poly-A tail?
histone mRNA molecules
During translation, what is the polarity of the synthesis of the polypeptide product?
Amino end to the carboxy terminus
What are the non-coding segments of mRNA?
introns
What is another name for “TATA” box required in the bacterial promotor for transcription to take place?
Prinbow box
Are eukaryotic mRNA molceuls monocistronic, polycistronic or both?
monocistronic
What is a toxin from certain mushrooms that inhibt RNA polymerase II?
α-amanitin
What protein factor is sometimes required for the termination of transcription?
ρ factor
What is an example of alternative splicing of eukaryotic primary pre-mRNA transcripts?(2 points)
The synthesis of the muscle proteins troponin T and tropomysin go through alternative splicing. Also, the surface immunoglobulins of unstimulated B cells go through alternative splicing
The activated amino acid is attached to what portion of the tRNA molecule?
The 3’ OH portion of the tRNA molecule
What are the two subunits that makes up prokaryotic ribosome?
30S and 50S
What type of mutation is known to cause β-thalassemia?
a mutation in the splice site of the β-thalassemia protein
Do Eukaryotic RNA polymerase require a protein factor to terminate transcription?
No
When it comes to the numbering system for a gene, the first base transcribed as RNA is efined as what?
The +1 base of that gene region
During transcription, is the RNA product parallel or antiparallel to the template DNA strand?
anti-parallel
Ribosomes translated the message in what direction of the mRNA?
5’ to 3’ direction
