Unit 3: quiz questions Flashcards
A TATA box associated with the human gene ABC is inactivated via mutation. Predict the effect on ABC.
-Sigma will no longer be able to leave the core promoter thereby blocking ABC mRNA elongation
-ABC transcription will proceed but at slower pace without TATA-dependent enhancer interaction
-The ABC gene will not be properly replicated during the next cell cycle
-The TBP portion of TFIID will no longer recognize the promoter for transcription of ABC mRNA
-The mutation will have no effect because human cells do not reply upon a TATA box.
-The TBP portion of TFIID will no longer recognize the promoter for transcription of ABC mRNA
Eukaryotes have 2 types of transcription factors, what are they?
General and “other”
General TF’s: terms that belong
-TFIID
-required for minimum levels of transcription
-part of the basal transcription apparatus
-bind to core promoter
“other” TF’s: terms that belong
-not required for transcription
-can bind to enhancer
-can increase or decrease the levels of transcription
-can bind to regulatory promoter
Which of the following is true about RNA interference?
-it generates tRNAs and siRNAs
-it occurs in both prokaryotes and eukaryotes
-it is a process that allows for tRNA to be appropriately spliced
-it requires an enzyme called dicer
-it requires an enzyme called dicer
Which of the following describes the terminator sequence in bacterial genes?
-5’ splice site
-consensus sequences in the core promoter
-inverted repeats followed by a string of adenines
-TATA box
inverted repeats followed by a string of adenines
The following diagram represents DNA that is part of the RNA-coding sequence of a transcription unit. The bottom strand is the template strand. Give the sequence found on the RNA molecule transcribed from this DNA and label the 5′ and 3′ ends of the RNA.
3′ ATAGGCGATGCCA 5′
5′ TATCCGCTACGGT 3′ ← Template strand
5’ ACCGUAGCGGAUA 3’
Which of the following is/are a part of pre-mRNA processing?
-removal of introns
-addition of a polyA tail
-addition of a 5’ cap
-joining of exons to introns
-removal of introns
-addition of a polyA tail
-addition of a 5’ cap
The following terms are a part of the splicing process. Create a concept map of these terms to describe this process.
3’ splice site
snRNPs
proteins
introns
snRNA
exons
lariat
5’ splice site
branch site
spliceosome
degradation
The following types of RNA must be processed in both prokaryotes and eukaryotes:
rRNA
tRNA
RNA interference directly prevents __________ from occurring.
Translation
Which of the following is true about transcription (select all that apply)?
RNA is made in a 5’ to 3’ direction
RNA is made antiparallel to the temple strand
only 1 of the 2 DNA strands is transcribed
DNA is made in a complementary and antiparallel manner
deoxyribonucleoside triphosphates are the substrates
DNA is the template for making RNA
RNA is made in a 5’ to 3’ direction
RNA is made antiparallel to the temple strand
only 1 of the 2 DNA strands is transcribed
DNA is the template for making RNA
Which of the following elements would NOT be found in an mRNA molecule?
start and stop codons
promoter
3’ untranslated region
protein-coding region
5’ untranslated region
promoter
Which of the following is the consensus sequence for the following set of nucleotide sequences?
T G G A G T T
A G C T G T T
T G C A A T A
A C G A G A A
T C C T G A T
T G C A A T T
T G C A G T T
A nontemplate strand on bacterial DNA has the following base sequence. What amino acid sequence will be encoded by this sequence?
5′–AAATTTCCCGGG–3′
Lys-Phe-Pro-Gly
A tRNA has the following anticodon: 3’ GCU 5’ Give all possible codons with which this tRNA can pair.
3’ AGC 5’
3’ GGC 5’
events of translation in the order in which they occur in initiation of prokaryotic protein synthesis
- IF-3 binds to small ribosomal subunit
- IF-3/small subunit bind to mRNA
- tRNA carrying n-formyl methionine + IF-2 + GTP all come in together and anticodon binds to start codon
- IF-1 binds to small ribosomal subunit
- GTP is hydrolyzed to GDP and all IF’s leave the complex
- large ribosomal subunit joins the complex
describe differences between prokaryotic and eukaryotic translation
Eukaryotic translation:
-ribosome scans the mRNA until it reaches the start codon
-small ribosomal subunit binds to the 5’ cap
-there are many more initiation factors involved
Prokaryotic translation:
-IF-1, IF-2, and IF-3 work during initiation of translation
-small ribosomal subunit binds to the Shine-Dalgarno sequence
If a ribosome has an amino acid chain attached to the tRNA in the P site, and an empty A site, the ribosome is waiting for:
EF-Tu to bring a charged tRNA to the A site
Which of the following is true regarding wobble?
-nonstandard base pairing can occur at the 3’ end of the anticodon and the 5’ end of the codon
-one codon is able to pair with more than one anticodon
-one anticodon is able to pair with more than one codon
one anticodon is able to pair with more than one codon
What serves as the co-repressor in the trp operon?
tryptophan
Consider a hypothetical operon that is controlled by an activator. When the activator is made, it is made in an inactive form. What describes this operon?
Positive Inducible
When trp is scarce in the cell, the trp operon initiates transcription because
Trp does not bind to the repressor protein, preventing the repressor protein from binding to the operator
Attenuation of the trp operon involves
-secondary structure formation in RNA molecules
-high tryptophan levels
-a 5’ UTR
