BCHM 4360 - Genes to Proteins Test #2 Latest
Update 2025-2026 Exam 370 Questions with
100% Verified Correct Answers Guaranteed A+
-once switch to lysis is hit... - CORRECT ANSWER: there is no going back (committed
to leaving)
-requires transcriptional changes in viral genome (inserted into bacteria)
"alternative pathway cooperation" model - CORRECT ANSWER: -C-terminal is
proposed to mediate cooperation between bound dimers, such that only one pair of
bound dimers forms
-under wild-type condition the pair binds to OR1 and OR2, and OR3 only binds at much
higher cI concentrations
-when OR1 is mutated, the pair binds to OR2 and OR3
-binding at OR1 and OR2 turns off PR and turns on PRM
3' end of tRNAs - CORRECT ANSWER: -have a conserved CCA sequence that serves
as attachment site for amino acid
3′ poly(A) tail in bacteria - CORRECT ANSWER: decreases stability
5' end of tRNAs - CORRECT ANSWER: -trimmed by RNase P
5' mRNA modification - CORRECT ANSWER: -The 5′ ends are capped with a 7-
methylguanine nucleotide via a 5′ -5′ triphosphate linkage
-This guanine is then methylated at N7
-The 5′ cap is needed for efficient elongation and termination of the transcript, for mRNA
processing and export from the nucleus, and for directing translation
,-In more complex eukaryotes, the 2′ O of the second and sometimes third base are
methylated
5′ capping and 3′ polyadenylation - CORRECT ANSWER: - are linked with each other
and with other RNA polymerization processes
-Capping is needed to allow RNA Pol II to continue transcription.
-Polyadenylation is needed for efficient transcription termination
-The C-terminal domain (CTD) of the largest subunit of RNA polymerase II, RPB1, is
responsible for mediating mRNA processing
a-cell gene expression - CORRECT ANSWER: a-specific genes: ON
α-specific genes: OFF
haploid-specific genes: ON
-MCM1 activates transcription of a-specific genes, which are not transcribed in α cells
a, α, and a/α cells gene expression - CORRECT ANSWER: -have distinctive gene
expression patterns, regulated by four proteins, a1, α1, α2, and MCM1
-these regulators are encoded at the MAT locus on chromosome III
-the MAT loci are different in different cell types: a cells encode a1, α cells encode α1
and α2
-MCM1 activates transcription of a-specific genes, which are not transcribed in α cells
-similar α1 activates transcription of α-specific genes in α cells, while α2 represses a-
specific gene transcription
-in a/α diploid cells, the a1 and α2 proteins combine to form a heterodimer which binds
different DNA sequences the monomers and represses haploid specific genes
-one of the repressed genes is α1, so α-specific genes are no longer transcribed
-another repressed gene is RME1, which represses meiosis genes, so when this is not
longer transcribed, meiosis is possible
,a/α-cell genes on/off - CORRECT ANSWER: a-specific genes: OFF
α-specific genes: OFF
haploid-specific genes: OFF
in a/α diploid cells, the a1 and α2 proteins combine to form a heterodimer which binds
different DNA sequences the monomers and represses haploid specific genes
-one of the repressed genes is α1, so α-specific genes are no longer transcribed
-another repressed gene is RME1, which represses meiosis genes, so when this is not
longer transcribed, meiosis is possible
abortive initiation - CORRECT ANSWER: -release of short RNAs of 2-9 nucleotides
because RNA polymerase frequently fails to make a full length RNA on the first attempt
-TBP bound to TATA = tether that holds RNA pol back
-RNA Pol attempts to go but fails -> everything must be there to leave promoter, tries to
leave but gets stuck
-involves bacterial sigma factor and eukaryotic TFIIB - both proteins have a loop that
extends into the RNA polymerase active site region
-the loop is in a position to block the elongating transcript, so the loop must be moved in
order for transcription to continue
activating transcription - CORRECT ANSWER: -enchancing the binding of RNA
polymerase to a promoter
-Ex: CAP activates more than 100 E. coli promoters when carbon sources are low
activation of RNA pol holoenzyme containing σ54 - CORRECT ANSWER: -needs to be
activated by ATP hydrolysis to drive promoter opening
-NtrC = example of one of these activators
activators - CORRECT ANSWER: proteins that increase transcription
, Addition of 5' cap - CORRECT ANSWER: -added in three stages, shortly after the
mRNA emerges from RNA Pol II (about 20-30 nucleotides)
1. First, an RNA 5′ triphosphate catalyzes removal of a phosphate from the 5′ end
2. Second, a guanyl transferase attaches a guanosine monophosphate (GMP) to the
end in a 5′ -5′ triphosphate linkage
3. Third, the guanine is methylated by a guanine-7-methyl transferase
-In yeast, the three steps are done by different enzymes
-The first two reactions are done by a single enzyme in C. elegans and mammals
addition of nucleotides to the mRNA strand - CORRECT ANSWER: -Ribonucleotides
(NTPs) enter the active site and base pair with the template strand
-successive nucleotides are added at the 3' end of the growing RNA molecule by
nucleophilic attack, forming a phosphodiester bond and releasing pyrophosphate (very
similar to DNA replication)
-the 5' end of the growing RNA leaves the polymerase via an exit channel
Addition of poly(A) tail - CORRECT ANSWER: -Polyadenylation at the 3′ end of
eukaryotic mRNAs starts with an initial cleavage
-This cleavage usually occurs after a CA that lies between a conserved AAUAAA
hexamer and a U or GU-rich region
-After cleavage, ~200 adenosines are added by poly(A) polymerase
-A larger protein complex is required for polyadenylation than for 5′ capping, probably
because it is more complex to recognize the different polyadenylation sites in different
mRNAs
adenine deaminases (ADARs) - CORRECT ANSWER: -responsible for editing
adenosine to inosine
Update 2025-2026 Exam 370 Questions with
100% Verified Correct Answers Guaranteed A+
-once switch to lysis is hit... - CORRECT ANSWER: there is no going back (committed
to leaving)
-requires transcriptional changes in viral genome (inserted into bacteria)
"alternative pathway cooperation" model - CORRECT ANSWER: -C-terminal is
proposed to mediate cooperation between bound dimers, such that only one pair of
bound dimers forms
-under wild-type condition the pair binds to OR1 and OR2, and OR3 only binds at much
higher cI concentrations
-when OR1 is mutated, the pair binds to OR2 and OR3
-binding at OR1 and OR2 turns off PR and turns on PRM
3' end of tRNAs - CORRECT ANSWER: -have a conserved CCA sequence that serves
as attachment site for amino acid
3′ poly(A) tail in bacteria - CORRECT ANSWER: decreases stability
5' end of tRNAs - CORRECT ANSWER: -trimmed by RNase P
5' mRNA modification - CORRECT ANSWER: -The 5′ ends are capped with a 7-
methylguanine nucleotide via a 5′ -5′ triphosphate linkage
-This guanine is then methylated at N7
-The 5′ cap is needed for efficient elongation and termination of the transcript, for mRNA
processing and export from the nucleus, and for directing translation
,-In more complex eukaryotes, the 2′ O of the second and sometimes third base are
methylated
5′ capping and 3′ polyadenylation - CORRECT ANSWER: - are linked with each other
and with other RNA polymerization processes
-Capping is needed to allow RNA Pol II to continue transcription.
-Polyadenylation is needed for efficient transcription termination
-The C-terminal domain (CTD) of the largest subunit of RNA polymerase II, RPB1, is
responsible for mediating mRNA processing
a-cell gene expression - CORRECT ANSWER: a-specific genes: ON
α-specific genes: OFF
haploid-specific genes: ON
-MCM1 activates transcription of a-specific genes, which are not transcribed in α cells
a, α, and a/α cells gene expression - CORRECT ANSWER: -have distinctive gene
expression patterns, regulated by four proteins, a1, α1, α2, and MCM1
-these regulators are encoded at the MAT locus on chromosome III
-the MAT loci are different in different cell types: a cells encode a1, α cells encode α1
and α2
-MCM1 activates transcription of a-specific genes, which are not transcribed in α cells
-similar α1 activates transcription of α-specific genes in α cells, while α2 represses a-
specific gene transcription
-in a/α diploid cells, the a1 and α2 proteins combine to form a heterodimer which binds
different DNA sequences the monomers and represses haploid specific genes
-one of the repressed genes is α1, so α-specific genes are no longer transcribed
-another repressed gene is RME1, which represses meiosis genes, so when this is not
longer transcribed, meiosis is possible
,a/α-cell genes on/off - CORRECT ANSWER: a-specific genes: OFF
α-specific genes: OFF
haploid-specific genes: OFF
in a/α diploid cells, the a1 and α2 proteins combine to form a heterodimer which binds
different DNA sequences the monomers and represses haploid specific genes
-one of the repressed genes is α1, so α-specific genes are no longer transcribed
-another repressed gene is RME1, which represses meiosis genes, so when this is not
longer transcribed, meiosis is possible
abortive initiation - CORRECT ANSWER: -release of short RNAs of 2-9 nucleotides
because RNA polymerase frequently fails to make a full length RNA on the first attempt
-TBP bound to TATA = tether that holds RNA pol back
-RNA Pol attempts to go but fails -> everything must be there to leave promoter, tries to
leave but gets stuck
-involves bacterial sigma factor and eukaryotic TFIIB - both proteins have a loop that
extends into the RNA polymerase active site region
-the loop is in a position to block the elongating transcript, so the loop must be moved in
order for transcription to continue
activating transcription - CORRECT ANSWER: -enchancing the binding of RNA
polymerase to a promoter
-Ex: CAP activates more than 100 E. coli promoters when carbon sources are low
activation of RNA pol holoenzyme containing σ54 - CORRECT ANSWER: -needs to be
activated by ATP hydrolysis to drive promoter opening
-NtrC = example of one of these activators
activators - CORRECT ANSWER: proteins that increase transcription
, Addition of 5' cap - CORRECT ANSWER: -added in three stages, shortly after the
mRNA emerges from RNA Pol II (about 20-30 nucleotides)
1. First, an RNA 5′ triphosphate catalyzes removal of a phosphate from the 5′ end
2. Second, a guanyl transferase attaches a guanosine monophosphate (GMP) to the
end in a 5′ -5′ triphosphate linkage
3. Third, the guanine is methylated by a guanine-7-methyl transferase
-In yeast, the three steps are done by different enzymes
-The first two reactions are done by a single enzyme in C. elegans and mammals
addition of nucleotides to the mRNA strand - CORRECT ANSWER: -Ribonucleotides
(NTPs) enter the active site and base pair with the template strand
-successive nucleotides are added at the 3' end of the growing RNA molecule by
nucleophilic attack, forming a phosphodiester bond and releasing pyrophosphate (very
similar to DNA replication)
-the 5' end of the growing RNA leaves the polymerase via an exit channel
Addition of poly(A) tail - CORRECT ANSWER: -Polyadenylation at the 3′ end of
eukaryotic mRNAs starts with an initial cleavage
-This cleavage usually occurs after a CA that lies between a conserved AAUAAA
hexamer and a U or GU-rich region
-After cleavage, ~200 adenosines are added by poly(A) polymerase
-A larger protein complex is required for polyadenylation than for 5′ capping, probably
because it is more complex to recognize the different polyadenylation sites in different
mRNAs
adenine deaminases (ADARs) - CORRECT ANSWER: -responsible for editing
adenosine to inosine
