Unit 5: Gene Expression Flashcards
How is DNA used to guide the synthesis of the new RNA molecule
a) template strand is read in a 5; to 3; direction synthesizing a new RNA molecule in the 3’ to 5’ direction
b) Template strand is read in a 3’ to 5’ direction synthesizing a new RNA molecule in the 5’ to 3’ direction
c) Non-template strand is read in a 5’ to 3’ direction synthesizing a new RNA molecule in the 3’ to 5’ direction
d) Non-template strand is read in a 3’ to 5’ direction synthesizing a new RNA molecule in the 5’ to 3’ direction
B)
Once synthesized, the new RNA molecule is identical sequence (with the exception that ‘T’ is replaced by ‘U’) to the…
a) Template strand of the original DNA
b) Non-template strand of original DNA
c) Neither the template nor the non-template strand
d) The template and non-template strands have the same sequence so its identical to both
b)
Put these events of transcription in chronological order:
1) sigma factor binds to the promoter region 2) the double helix of DNA is unwound, breaking apart the complementary strands
3) sigma factor binds to RNA polymerase
4) Sigma factor is released
5) Transcription begins
a) 1-2-3-4-5
b) 2-3-1-4-5
c) 3-1-2-5-4
d) 3-2-1-4-5
c)
How are RNA hairpins related to termination?
a) The hairpins are formed from complementary base pairing and cause separation of the RNA transcript and RNA polymerase
b) A three-base repeat signals a stop sequence, and the RNA transcript is released
c) Release factors bind to sites on the hairpin turn, causing release of the RNA transcript
d) The hairpin turn prevents more NTPs from entering the active site of the enzyme, effectively shutting off the process of polymerization
a)
Which statement is/are correct as they concern prokaryotic transcription
a) Promoters are located on the template strand
b) Promoters are located on the non-template strand
c) RNA polymerase synthesizes the new RNA molecule in a 3’ to 5’ directtion
d) b and c
e) a and c
b)
Which of the following is possible in prokaryotes, but not in eukaryotes
a) post-transcriptional splicing
b) concurrent transcription and translation
c) translation in the absence of a ribosome
d) gene regulation
b)
Which of the following occurs in a eukaryotic but not in a prokaryotic transcription
a) Addition of a 5’-7-methylguanosine cap
b) Addition of a 3’-poly-A tail
c) Recognition of a TATA boxes by sigma factor
d) both a and b
e) all of the above
d) sigma factor only found in prokaryotes - RNA polymerase II only found in eukaryotes
What molecule/feature ensures that the correct amino acid is added to the peptide chain with reading of a specific codon during translation?
a) methyl-guanosine cap of a properly modified mRNA
b) poly(A) tail of a properly modified mRNA
c) CCA sequence at the 3’ end of the tRNA
d) properly assembled RNA polymerase holoenzyme
e) anticodon of a properly loaded aminoacyl tRNA
e)
How does termination of translation take place?
a) the ribosome reaches the end of the mRNA molecule
b) The supply of loaded tRNAs is depleted
c) Stop codons with no corresponding tRNAs are read
d) Hairpin turns of mRNA force the ribosome off the mRNA
e) Energy depletion causes termination
c)
Post-translational modifications of proteins include all of the following except:
a) Removal of introns
b) Alteration to the protein structure through proteolysis
c) Addition of carbohdyrate to form a glycoprotein
d) Addition of phosphate groups to serine residues
a)
The original DNA has the base sequence AGCGTTACCGT; a mutation in the DNA strand results in the base sequence AGGCGTTACCGT. Based on this information, what can you conclude about the mutation?
a) There was a deletion of a single base, which is likely to have a minimal effect on the protein
b) There was an insertion of a single base, which will most likely result in a single amino acid change in the protein being coded by this sequence
c) There was an insertion of a single base, which is likely to have minimal effect on the protein
d) There was insertion of a single base leading to a frameshift mutation, which is likely to have a major effect on the protein
d)
These segments of DNA where transcription begins and are located on the non-template (coding) strand. These segments are known as:
a) sigma
b) the holoenzyme
c) initiation factor
d) promoters
e) start codons
d)
Which molecule or reaction supplies the energy for polymerization of nucleotides in the process of transcription?
a) the interaction between RNA plymerase and the promoter
b) the phosphate bonds in the NTPs that serve as building blocks
c) the energy released when hydrogen bonds are broken as DNA molecule is unwound
d) ATP, through its incorporation into the growing nucleic acid
b)
_____ are molecules that recognize key sequences in promoters of eukaryotic genes, and thus help position RNA polymerase II
a) sigma factors
b) snRNPs
c) TATA binding proteins
d) Ribozymes
e) aminoacyl tRNA synthetases
c)
Eukaryotes have three nuclear RNA polymerases. The primary function of RNA polymerase II is transcription of:
a) only rRNA-coding genes
b) only tRNA-coding genes
c) both rRNA and tRNA-coding genes
d) protein-coding genes
d)
