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BCHM 4360 EXAM 2 LATEST 2026-2027 ACTUAL EXAM WITH
COMPLETE QUESTIONS AND CORRECT DETAILED ANSWERS (100%
VERIFIED ANSWERS) |ALREADY GRADED A+| ||PROFESSOR
VERIFIED|| ||BRANDNEW!!!||
What is the main difference between the many bacterial sigma
factors? - ANSWER-Each has a preferred binding sequence and
preferred spacing between the -35 and -10 elements
How do the sigma factor preferred spacings help regulate
transcription? - ANSWER-The closer the sequences and spacing
are to the preference for a particular sigma factor, the tighter the
sigma factor will bind, giving higher transcription rates
What are most common for strong promotion of expression of
genes? - ANSWER-Consensus sequences
What does Domain 2 of the RNA Polymerase holoenzyme bind to
and what is its function? - ANSWER--10 region, helps separate
duplex DNA (promoter melting)
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What does Domain 3 of the RNA Polymerase holoenzyme bind to
and what is its function? - ANSWER-two bases of the extended -
10 region
What does Domain 4 of the RNA Polymerase holoenzyme bind to
and what is its function? - ANSWER--35 element, attached to
flexible part of core enzyme which may let it accomodate different
-35 to -10 spacings
What are pro and anti sigma factors? - ANSWER-Pro-sigma
factors have inhibitory domains that must be cleaved before the
sigma can associate with the core enzyme. Anti-sigma factors are
proteins that bind to sigma factors and inhibit their function
Explain the example of how anti-sigma factors are involved in the
regulation of flagellum assembly in S. typhimurium. - ANSWER-1.
While the proteins that form the flagellum base are being
synthesized, the anti-sigma binds to the sigma factor, preventing
it from binding to the holoenzyme
2. The sigma factor promotes transcription of genes that are
needed for completion of flagellum assembly
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3. In the late stages of flagellum protein synthesis, the anti-sigma
factor is exported from the cell so the sigma factor can promote
assembly gene transcription, allowing the flagellum to be put
together.
Eukaryotic and archaeal promoters also need extra proteins to
target the core enzyme to promoters: _______ _____________
_______. - ANSWER-general transcription factors
The TFII complex works with RNA Polymerase ___ to form the
___-_________ complex. - ANSWER-II, pre-initiation
What is the function of TFIIA? - ANSWER-stabilizes binding of
TBP and TFIIB
What is the function of TFIIB? - ANSWER-promoter recognition,
stabilizes early transcription complex
What is the function of TFIID? - ANSWER-promoter recognition,
DNA bending interacts with regulatory factors
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What is the function of TFIIE? - ANSWER-recruits TFIIH
What is the function of TFIIF? - ANSWER-suppresses non-
specific DNA binding and captures non-template strand upon
melting
What is the function of TFIIH? - ANSWER-unwinds promoter
DNA, phosphorylates CTD
True or False: All eukaryotic polymerases need the TATA binding
protein (TBP) to initiate transcription. - ANSWER-True
What are three other elements besides the TBP or TATA box that
are often present in eukaryotic transcription? - ANSWER-TFIIB
recognition element (BRE), initiator element (INR), and
downstream promoter element (DPE)
BCHM 4360 EXAM 2 LATEST 2026-2027 ACTUAL EXAM WITH
COMPLETE QUESTIONS AND CORRECT DETAILED ANSWERS (100%
VERIFIED ANSWERS) |ALREADY GRADED A+| ||PROFESSOR
VERIFIED|| ||BRANDNEW!!!||
What is the main difference between the many bacterial sigma
factors? - ANSWER-Each has a preferred binding sequence and
preferred spacing between the -35 and -10 elements
How do the sigma factor preferred spacings help regulate
transcription? - ANSWER-The closer the sequences and spacing
are to the preference for a particular sigma factor, the tighter the
sigma factor will bind, giving higher transcription rates
What are most common for strong promotion of expression of
genes? - ANSWER-Consensus sequences
What does Domain 2 of the RNA Polymerase holoenzyme bind to
and what is its function? - ANSWER--10 region, helps separate
duplex DNA (promoter melting)
,2|Page
What does Domain 3 of the RNA Polymerase holoenzyme bind to
and what is its function? - ANSWER-two bases of the extended -
10 region
What does Domain 4 of the RNA Polymerase holoenzyme bind to
and what is its function? - ANSWER--35 element, attached to
flexible part of core enzyme which may let it accomodate different
-35 to -10 spacings
What are pro and anti sigma factors? - ANSWER-Pro-sigma
factors have inhibitory domains that must be cleaved before the
sigma can associate with the core enzyme. Anti-sigma factors are
proteins that bind to sigma factors and inhibit their function
Explain the example of how anti-sigma factors are involved in the
regulation of flagellum assembly in S. typhimurium. - ANSWER-1.
While the proteins that form the flagellum base are being
synthesized, the anti-sigma binds to the sigma factor, preventing
it from binding to the holoenzyme
2. The sigma factor promotes transcription of genes that are
needed for completion of flagellum assembly
,3|Page
3. In the late stages of flagellum protein synthesis, the anti-sigma
factor is exported from the cell so the sigma factor can promote
assembly gene transcription, allowing the flagellum to be put
together.
Eukaryotic and archaeal promoters also need extra proteins to
target the core enzyme to promoters: _______ _____________
_______. - ANSWER-general transcription factors
The TFII complex works with RNA Polymerase ___ to form the
___-_________ complex. - ANSWER-II, pre-initiation
What is the function of TFIIA? - ANSWER-stabilizes binding of
TBP and TFIIB
What is the function of TFIIB? - ANSWER-promoter recognition,
stabilizes early transcription complex
What is the function of TFIID? - ANSWER-promoter recognition,
DNA bending interacts with regulatory factors
, 4|Page
What is the function of TFIIE? - ANSWER-recruits TFIIH
What is the function of TFIIF? - ANSWER-suppresses non-
specific DNA binding and captures non-template strand upon
melting
What is the function of TFIIH? - ANSWER-unwinds promoter
DNA, phosphorylates CTD
True or False: All eukaryotic polymerases need the TATA binding
protein (TBP) to initiate transcription. - ANSWER-True
What are three other elements besides the TBP or TATA box that
are often present in eukaryotic transcription? - ANSWER-TFIIB
recognition element (BRE), initiator element (INR), and
downstream promoter element (DPE)
