BCH403 EXAM REVIEW
QUESTIONS WITH CORRECT
DETAILED ANSWERS
RNA polymerase holoenzyme - Answer-Complete enzyme complex for transcription
initiation, including core enzyme and sigma factor.
Promoter - Answer-DNA sequence where transcription starts.
Transcription bubble - Answer-Opened DNA region where transcription occurs.
Scrunching - Answer-Accumulation of DNA in the polymerase during early transcription.
Abortive initiation - Answer-Early, short RNA transcripts that are released before
elongation.
Terminator - Answer-DNA sequence that signals transcription termination.
Consensus nucleotide sequence / sequence logo - Answer-A general or average
sequence pattern recognized by proteins (e.g., promoters).
General transcription factors - Answer-Proteins needed to initiate transcription by RNA
polymerase II.
TATA sequence - Answer-Promoter element in eukaryotic DNA, often near transcription
start site.
TBP - Answer-TATA-binding protein; essential part of transcription initiation complex.
Transcription initiation complex - Answer-Assembly of proteins that starts transcription.
Transcriptional activator - Answer-Protein that increases gene transcription.
Transcription enhancer - Answer-DNA element that increases transcription from a
distance.
Mediator - Answer-Protein complex linking activators to RNA polymerase II.
Elongation factor - Answer-Protein that aids in RNA chain elongation.
, DNA Supercoiling - Answer-Over- or under-winding of DNA, influencing structure and
function.
RNA splicing - Answer-Removal of introns and joining of exons in pre-mRNA.
Capping - Answer-Addition of a modified guanine nucleotide to the 5' end of mRNA.
Polyadenylation - Answer-Addition of a poly(A) tail to the 3' end of mRNA.
CTD (C-terminal domain) - Answer-Tail of RNA polymerase II, involved in RNA
processing.
CBC (Cap-binding complex) - Answer-Proteins that bind to the 5' cap of mRNA, aiding
stability and export.
Alternative splicing - Answer-Process by which different mRNAs are generated from the
same gene.
snRNP - Answer-Small nuclear ribonucleoproteins; core components of the
spliceosome.
Spliceosome - Answer-Complex that carries out RNA splicing.
Kinetic Proofreading - Answer-Mechanism increasing accuracy by using time delays to
detect mismatches.
EJC (Exon Junction Complex) - Answer-Protein complex marking exon-exon junctions
after splicing.
Exon definition - Answer-Mechanism by which exons are recognized during splicing.
Splicing enhancers - Answer-Sequences that promote exon inclusion during splicing.
Self-splicing RNA - Answer-RNA that can remove its own introns without proteins.
CstF - Answer-Cleavage stimulation factor; involved in 3' end processing of pre-mRNA.
CPSF - Answer-Cleavage and polyadenylation specificity factor; binds to poly(A)
signals.
PAP (Poly(A) polymerase) - Answer-Enzyme that adds adenine residues to the 3' end of
RNA.
RNA exosome - Answer-Multi-protein complex that degrades RNA.
QUESTIONS WITH CORRECT
DETAILED ANSWERS
RNA polymerase holoenzyme - Answer-Complete enzyme complex for transcription
initiation, including core enzyme and sigma factor.
Promoter - Answer-DNA sequence where transcription starts.
Transcription bubble - Answer-Opened DNA region where transcription occurs.
Scrunching - Answer-Accumulation of DNA in the polymerase during early transcription.
Abortive initiation - Answer-Early, short RNA transcripts that are released before
elongation.
Terminator - Answer-DNA sequence that signals transcription termination.
Consensus nucleotide sequence / sequence logo - Answer-A general or average
sequence pattern recognized by proteins (e.g., promoters).
General transcription factors - Answer-Proteins needed to initiate transcription by RNA
polymerase II.
TATA sequence - Answer-Promoter element in eukaryotic DNA, often near transcription
start site.
TBP - Answer-TATA-binding protein; essential part of transcription initiation complex.
Transcription initiation complex - Answer-Assembly of proteins that starts transcription.
Transcriptional activator - Answer-Protein that increases gene transcription.
Transcription enhancer - Answer-DNA element that increases transcription from a
distance.
Mediator - Answer-Protein complex linking activators to RNA polymerase II.
Elongation factor - Answer-Protein that aids in RNA chain elongation.
, DNA Supercoiling - Answer-Over- or under-winding of DNA, influencing structure and
function.
RNA splicing - Answer-Removal of introns and joining of exons in pre-mRNA.
Capping - Answer-Addition of a modified guanine nucleotide to the 5' end of mRNA.
Polyadenylation - Answer-Addition of a poly(A) tail to the 3' end of mRNA.
CTD (C-terminal domain) - Answer-Tail of RNA polymerase II, involved in RNA
processing.
CBC (Cap-binding complex) - Answer-Proteins that bind to the 5' cap of mRNA, aiding
stability and export.
Alternative splicing - Answer-Process by which different mRNAs are generated from the
same gene.
snRNP - Answer-Small nuclear ribonucleoproteins; core components of the
spliceosome.
Spliceosome - Answer-Complex that carries out RNA splicing.
Kinetic Proofreading - Answer-Mechanism increasing accuracy by using time delays to
detect mismatches.
EJC (Exon Junction Complex) - Answer-Protein complex marking exon-exon junctions
after splicing.
Exon definition - Answer-Mechanism by which exons are recognized during splicing.
Splicing enhancers - Answer-Sequences that promote exon inclusion during splicing.
Self-splicing RNA - Answer-RNA that can remove its own introns without proteins.
CstF - Answer-Cleavage stimulation factor; involved in 3' end processing of pre-mRNA.
CPSF - Answer-Cleavage and polyadenylation specificity factor; binds to poly(A)
signals.
PAP (Poly(A) polymerase) - Answer-Enzyme that adds adenine residues to the 3' end of
RNA.
RNA exosome - Answer-Multi-protein complex that degrades RNA.
