Ch. 12 Bio
A 5'-CUA-3' codon in an mRNA could be recognized by which of the following anticodon sequences in a tRNA?
3'-GAU-5'
If a protein in the coactivator complex does not function properly, what would be a consequence?
Activators and repressors will not be able to properly effect the rate of transcription
A large region of a promoter has been deleted upstream of a gene. What effect will this have on transcription of the gene?
Basal transcription factors won't bind to the template DNA, so RNA polymerase will not bind to the template DNA, so transcription will not occur
A molecule found in the nucleus of cell that contains the cell's genome
DNA
Which of the following best describes transcription
DNA -> RNA
During translation elongation, amino acids are brought to the ribosome with the help of
EF-Tu
Look at the sequence of DNA in the normal and diseased individual. Using the Genetic Code, determine which amino acid has replaced which?
Glutamic acid has switched to aspartic acid
Using Table 3.14, characterize the amino acids that have been substituted in the normal and mutant proteins, glutamic acid to valine.
Glutamic acid is acidic and polar, valine in nonpolar
RNA polymerase is able to open the DNA double helix as it moves down the template. What type of enzymatic activity does this mean RNA polymerase must possess? Polymerase activity
Helicase activity
All nascent proteins being with what amino acid?
Methionine
Which of the following statements about termination is TRUE?
No tRNA can recognize a stop codon. It is recognized by a release factor protein.
How does the ribosome recognize the proper tRNA to bind?
Only a tRNA with an anticodon that is complementary to the codon will bind in the A-site
The initiating transfer RNA, carrying formylmethionine, binds to which site?
P site
tRNAs and rRNAs transcribes what genes?
RNA polymerase 1 and 2
protein coding transcribes what gene(s)
RNA polymerase 2
During the process of transcription in a eukaryote
RNA polymerase synthesizes new nucleotide chains in the 5' to 3' direction.
What would happen if the sigma factor didn't bind to the RNA polymerase?
RNA polymerase would not bind to the template DNA
The enzyme that accomplishes transcription is termed
RNA polymerase.
Why is RNA synthesis called 'transcription' and protein synthesis called 'translation?'
RNA synthesis makes a complementary copy of the DNA using nucleic acid and protein synthesis requires the information in the RNA to be changed into a different type of molecule
RNA processing does NOT involve which of the following?
Removal of exons
Forms part of the enzyme that drives translation
Ribosomal RNA & Ribosomal protein
List events of transcription
Rna Polymerease binds to promoter>DNA is unwound, RNA is synthesized in the 5'->3' >RNA polymerase reaches the > The new mRNA is released.
A single point mutation has occurred in a gene causing a stop codon to appear early in the translation of the protein. What effect will this have on the protein?
The early stop codon will cause termination to occur earlier, and the protein will be abnormally short.
There is an error during the transcription of a gene, what will be the consequence?
The final protein might not be functional
The formation of a bond between the peptide in the P site and the amino acid in the A site
The formation of a bond between the peptide in the P site and the amino acid in the A site
What stimulates the ribosome to move down one codon?
The formation of a bond between the peptide in the P site and the amino acid in the A site
A mutation occurred in the third codon position of a gene, but the protein still functions normally. How is this possible?
The genetic code is redundant, so that mutations in the third position of the codon often result in the same amino acid being specified.
Why is GTP used during the initiation of translation?
To facilitate the binding of the mRNA, and the initiator tRNA to the ribosome
Which of the following occurs first in transcription?
formation of a holoenzyme
A difference between bacterial and eukaryotic transcription
in eukaryotes, there are different RNA polymerases (I, II, and III).
Which of the following is correct regarding sigma factor?
it recognizes the promoter region
The Shine-Dalgarno sequence is found on the ________.
mRNA
The molecule that contains the genetic information for the production of a structural gene.
mRNA
Which of the following is not involved in the initiation of translation?
mRNA
Contains information to be translated (as codons)
mRNA & Genes
During the process of translation in a eukaryote
mRNA interacts with ribosomes in the cytoplasm.
A difference between bacterial and eukaryotic translation is
modifications to the 5' end of mRNA help it to bind to ribosomes only in eukaryotes
The amino acids carried by the transfer RNA are joined by
peptide bonds.
The transcription enzyme first attaches to the ________ of the gene. The transcription enzyme first attaches to the ________ of the gene.
promoter
The segment of the DNA molecule where messenger RNA synthesis begins is called the
promoter region
Translation is the synthesis of
proteins from mRNA.
The protein that promotes translation termination is called
release factor
The snRNPs are also called
snurps.
The reason that the genetic code can correctly specify the order of amino acids in a polypeptide is
specific tRNAs become attached to specific amino acids.
Structural RNA that lnks an amino acid to an antcodon
tRNA
The Rho protein is involved in the _____ stage of transcription
termination
Which part of the protein is formed during termination?
Free carboxylic acid group
Which of the following best describes translation?
RNA -> Protein
Arrange the following in the proper sequence in which they occur during RNA splicing. 1. Lariat is formed 2. U2 binds to branch site 3. 3' splice site is cut
2, 1, 3
The complimentary messenger RNA strand that would be synthesized from the DNA base sequence of 5' CTGAC 3' would be
3' GACUG 5'
Study the RNA sequence below and determine where the boundaries of an intron could be. Select the answer that includes the entire intron in red.
5' ...CCGAGGUACGAUUUGAGUCGGCUACAGUAUUGA.... 3'
Which of the following do snRNPs bind to?
5' and 3' ends of the intron
The genetic code consists of ____ codons that specify amino acids, and ____ codons that do not specify amino acids.
61/3
New amino acids (other than the initial f-Met) enter at which site?
A
Translation is terminated when a stop codon is presented at the ________ site.
A
Which of the following statements below is TRUE? (?2)
A complex disease like sickle cell anemia is due to the substitution of a single amino acid in a single protein
What is the difference in the amino acid sequence (and therefore the protein) of the normal individual and that of the individual with sickle cell anemia?
A single amino acid has been changed
What is the difference in the DNA sequence of the normal individual and that of the individual with sickle cell anemia?
A single base has been changed
Which of the following statements below is TRUE? (?1)
A single point mutation in the DNA sequence leads to a change in the protein structure, which leads to a change in the protein's function and causes sickle cell anemia
Translation is terminated when a stop codon is presented at the
A site.
The terminator of a gene is located upstream of the coding region. TRUE or FALSE
False
The three base sequence on the transfer RNA is the codon. True or False
False
Introns are generally considered 'free to mutate,' meaning that if a mutation occurs within the intron, it will not effect the functional protein. What is an exception to this axiom?
If there is a mutation in the 3' or 5' splice site, the snurp won't recognize it, and it will not be removed from the mRNA
What is a difference between DNA replication and RNA transcription?
In DNA replication the helix is never closed after it is opened by helicase, but once RNA polymerase has finished transcribing a region the double helix closes
How is GTP used during elongation?
It aids in the binding of the incoming tRNA to the A site of the ribosome AND It aids in translocating the ribosome one codon down the mRNA
What is unusual about the initiator tRNA?
It carries a modified amino acid
Which of the following statements about peptidyl transferase is TRUE?
It catalyzes the formation of peptide bonds and It is present in the 50S ribosomal subunits.
Bicyclomycin is an antibiotic that is effective against many gram negative bacteria. It works by inhibiting Rho. What direct effect would this have on a bacteria?
It would prevent termination of RNA transcription, causing mRNA transcripts to be abnormally long.
A molecule made of amino acids that correspond to the genetic information in a structural gene
Polypeptide
Why do eukaryotes require a 5' cap and a poly-A tail but prokaryotes don't?
Prokaryotes don't need to transport their RNA out of the nucleus, so they don't need these features
If the rho protein did not bind to the RNA, what might be the consequence?
The RNA polymerase would not dissociate from the RNA and the template DNA
How do you know that the gene being transcribed in the animation is a prokaryote?
The initiation of transcription involves a sigma factor
If the Shine-Delgarno sequence was mutated, what might be a consequence?
The mRNA would not bind to the small ribosomal subunit in the proper location
There is an error during translation of a gene, what will be the consequence?
The protein might not be functional
If an aminoacyl-tRNA synthetase added the wrong amino acid to a tRNA, what would happen?
The tRNA would carry the worng amino acid, and it would be incorporated into the growing protein
Why are nucleotide triphosphates used to polymerize RNA?
The triphosphate is a high energy molecule so that polymerization is spontaneous
Evaluate the statements below and determine which is the best reason for why eukaryotes use basal transcription factors?
They give the cell tight control over transcription
What changes would a scientist want to make to a eukaryotic gene before they insert it into a bacterial chromosome to be expressed?
They should remove the introns
Which of the following statements about structural gene is TRUE?
Transcription of structural genes requires DNA sequences that are not part of the gene itself
The synthesis of an RNA copy of a gene
Transcripton
The synthesis of a specific sequence of amino acids on a ribosome.
Translation
Eukaryotic transcription factors include activators and coactivators. True or False
True
The amino acid sequence of a protein determines its shape and specific function. TRUE OR FALSE?
True
At what point in gene expression do molecules go from being information storage molecules to metabolic and structurally functional molecules?
When RNA is translated into protein
Which of the following statements about eukaryotic mRNA is TRUE?
a cap is added to their 5' end, a poly-A tail is added to their 3' end, and each usually specifies only a single protein
The genetic code is degenerate. That means
a particular amino acid can be specified by more than one codon.
Which of the following does not occur during the processing of eukaryotic mRNA?
a ribosome recognition sequence is added
There is only one start codon, AUG. This means that
all newly-made polypeptides have a methionine at their amino end.
Which of the following statements about RNA splicing is FALSE?
all of these choices are true
In eukaryotes, transcription to produce an mRNA must occur in
the nucleus, where the chromosomal DNA is found
Which of the following occurs as a result of translocation?
the tRNA that was in the P site moves into the E site
Which of the following occurs as the ribosome shifts down the mRNA by a distance of three nucleotides?
the tRNA that was in the P site moves into the E site
A characteristic shared by eukaryotic mRNA, tRNA, and ribosomal RNA is that...
they are all transcribed from DNA
Which of the following statement(s) about basal transcription factors is(are) TRUE?
they are essential for transcription and they cannot increase the rate of transcription by themselves
The structure that causes the synthesis of RNA to cease is known as the
transcription terminator
At the E site
transfer RNA is released
Which of these events occur as a prokaryotic mRNA is being transcribed?
translation of protein
Splicing joins together
two exons
The assembly of transcription factors begins
upstream from the transcription start site.
