KEMGEN LE2

What does this likely describe?

1 RNA polymerase used in all transcription processes

• cheek cell

• bacterial cell

• stem cells

• unipotent cell

Answer explanation

in the lab, transcription was found to be inhibited at low levels of a-amanitin, the product of this process is likely

• rRNA

• pre-mRNA

• mRNA

• tRNA

Answer explanation

RNA pol II: inhibit at low concs

RNA pol III: inhibit at high concs

RNA pol I: quite resistant to

What is true about RNA polymerase

• Slow growth at many sites, no primer, proofreading

• Rapid growth at few sites, no primer, no proofreading

• Slow growth at many sites, no primer, no proofreading

• Rapid growth at few sites, primer, proofreading

Answer explanation

subunit of prokaryotic RNA polymerase for promoter recognition

• β

• β'

• α

• σ

• ω

Answer explanation

α and ω are conserved because of their important functions

What purpose do Mg2+ ions serve

• catalyst

• stabilization

• unwinding

• energy source

Answer explanation

inducible: experssion of gene needs effector

constitutive: constant expression no matter the cell condition

Where is TATA box found

• right before the transcription start site

• about 100 bp away from start site

• 10 bp away from start site

• 35 bp away from start site

Answer explanation

this promoter region is what the σ subunit recognizes

DNA footprinting is used to identify the promoter sequences, what explains why are the binding sites characterized by missing bands

• binding protein degrades the DNA and thus isnt visualized with radiography

• binding protein, even if radioactive, does not show up because of the interaction of gel in electrophoresis

• binding protein does not travel in gel so the bands do not show up at all

• binding protein covers radioactive markers in DNA so it is not visualized in radiography

Answer explanation

What is formed first?

• open promoter complex

• closed promoter complex

• helicase to generate open promoter complex

• ribosomal subunits

Answer explanation

How is DNA unwound without helicase?

• residues in the transcription site are removed to destabilize the template DNA

• residues in TATA box are flipped to de-anneal double stranded DNA

• alpha subunit in RNA polymerase binds to DNA more favorably than H bonds and base stacking

• metal cofactors cut the H bonds between nitrogenous bases in DNA

Answer explanation

Release of ______ provides energy for elongation (nucleophilic attack of 3' in nucleotide chain)

• ATP

• GTP

• PPi

• Nitrogenous base

Answer explanation