3928071
Questão 1
Questão
How is the order of nucleotides in mRNA used to generate the linear sequences of amino acids in protein?
Responda
-
process known as translation
-
process know as transcription
-
process know as post translational modifications
Questão 2
Questão
What process is the most highly conserved across all organism and the most energetically costly?
Responda
-
translation
-
transcription
-
cellular respiration
Questão 3
Questão
Transcription is a more formidable challenge than translation.
Responda
- True
- False
Questão 4
Questão
The hydrophobic side chains of phenylalanine, tyrosine, and tryptophan forms interactions with the mRNA template.
Responda
- True
- False
Questão 5
Questão
Crick proposed a [blank_start]special adaptor[blank_end] molecule that directly interacts with the coding units of mRNA. He proposed to also be a [blank_start]RNA[blank_end] molecule.
Responda
-
RNA
-
special adaptor
Questão 6
Questão
amino acids that are attached to a class of RNA molecules that represent 15% of all celluar RNA and transfer amino acids to a growing polypeptide chain.
Responda
-
tRNA
-
rRNA
-
mRNA
Questão 7
Questão
The translation machinery is comprised of ?
Responda
-
mRNAs
-
tRNAs
-
aminoacyl-tRNA synthetases (aaRS)
-
ribosome
-
rRNA
-
DNA
Questão 8
Questão
The competent of the translation machinery are always discarded after use.
Responda
- True
- False
Questão 9
Questão
Provides the information to be interpreted by translation machinery
Responda
-
DNA
-
mRNA
-
amino acids
Questão 10
Questão
This region of the mRNA specifies the order of amino acids by the ordered series of 3-nucleotide-long units called codons?
Responda
-
introns
-
poly A tail
-
protein coding region
Questão 11
Questão
couple amino acids to specific tRNAs that recognize the appropriate codon?
Responda
-
ribozymes
-
aminoacyl tRNA synthetase
-
poly-a-polymerase
Questão 12
Questão
coordinates correct recognition of mRNA by each tRNA and catalyzes peptide bond formation between growing peptide chain and amino acids attached to tRNA
Responda
-
ribosomes
-
ribozymes
-
transferase
Questão 13
Questão
in mRNA containing 2 or more open reading frames that can encode for multiple polypeptide chains
Responda
-
eukaryotic
-
prokaryotic
Questão 14
Questão
protein coding regions of each mRNA is composed of contiguous, non-overlapping string of codons called?
Responda
-
protein coding region
-
origin of replication
-
ORF
Questão 15
Questão
Eukaryotes, contain a single ORF that encode for multiple protein which is called polycistronic.
Responda
- True
- False
Questão 16
Questão
translation starts at the [blank_start]5'[blank_end] end of ORF and proceeds into the 3' end
Responda
-
5'
-
3'
Questão 17
Questão
Start codons in bacteria
Responda
-
AUG
-
GUG
-
UUG
-
UAA
-
UGA
Questão 18
Questão
eukaryotic cells always use AUG as a stop codon
Responda
- True
- False
Questão 19
Questão
fundamental unit of an ORF is a [blank_start]codon[blank_end]
Responda
-
codon
Questão 20
Questão
What are the important functions of a start codon?
Responda
-
specify first amino acid incorporation
-
contains special interactions with tRNA for protein synthesis
-
defines the reading frame for all subsequent codons
-
allows for hydrogen bonding to other bases
Questão 21
Questão
Since the codons are a 3-nucleotide long, any stretch of mRNA could be translated in three different reading frames by overlapping.
Responda
- True
- False
Questão 22
Questão
Stop codons are UAG,UGA and UAA in both eukaryotes and prokaryotes
Responda
- True
- False
Questão 23
Questão
Eukaryotic mRNA recruit ribosomes by the shine-dalgarno sequence which is ribosome binding site(RBS) that recruit the translation machinery.
Responda
- True
- False
Questão 24
Questão
the ribosome binding site
Responda
-
binds with the 16s rRNA of the ribosome
-
has a sequnce of CCUCCU
-
always has poor spacing
-
in all prokaryote has strong binding
Questão 25
Questão
limited complementarity and poor spacing promotes active translation
Responda
- True
- False
Questão 26
Questão
some prokaryotes lack a strong RBS but can still be actively translated by having a start and a stop codon right next to each other.
Responda
- True
- False
Questão 27
Questão
who uses their 5' and 3' modified ends to facilitate translation?
Responda
-
bacteria
-
prokaryotes
-
eukaryotes
Questão 28
Questão
Kozak sequence
Responda
-
a purine, three bases upstream of the start codon and a guanine downstream
-
extreme 5' end
-
presence
-
scanning
-
interacts with initiator tRNA
Questão 29
Questão
5' cap allows the ribosome to be recruited in order to go through a process called scanning.
Responda
- True
- False
Questão 30
Questão
[blank_start]poly-A-tail[blank_end] at the end of mRNA enhances the level of translation of mRNA by promoting efficient recycling of [blank_start]ribosomes[blank_end].
Responda
-
poly-A-tail
-
ribosomes
Questão 31
Questão
[blank_start]tRNA[blank_end] molecules are 75 to 95 ribonucleotides in length which there are many types of.
Responda
-
tRNA
Questão 32
Questão
The site at which amino acid is attached by the enzyme aminoacyl tRNA syntheses?
Responda
-
D loop
-
5'CCA3'
-
anticodon loop
-
TYC loop
Questão 33
Questão
Unusual bases found in tRNAs primary structure created by post-transcriptional modifications?
Responda
-
pseudouridine
-
dihydrouridine
-
hypoxanthine
-
uridine
Questão 34
Questão
principle features of the tRNA clover leaf are
Responda
-
acceptor stem
-
YU loop
-
D loop
-
anticodon loop
-
constant loop
-
variable loop
Questão 35
Questão
L-shape reveals the secondary structure of tRNA, which is stabilized by hydrogen bonds only.
Responda
- True
- False
Questão 36
Questão
charged tRNAs have an amino acid attached to them by amino alkyl linkage
Responda
- True
- False
Questão 37
Questão
acyl linkage is a high energy bond that is hydrolysis results in a large change in free energy, which helps drive the formation of peptide bonds
Responda
- True
- False
Questão 38
Questão
step one of aminoacyl-tRNA charging is [blank_start]adenylyation[blank_end] which amino acid reacts with ATP, amino acid is attached to adenylic acid via group transfer ester bond.
Responda
-
adenylyation
Questão 39
Questão
Whats the driving force that make adenylaltion energetically favorable reaction?
Responda
-
the release of pyrophosphate (PPI)
-
hydrolysis of pyrophosphate (PPi)
Questão 40
Questão
In step two of aminoacyl tRNA-charging- the adenylylated amino acid which is highly bound to the synthetase reacts with?
Responda
-
tRNA
-
PPI
-
another amino acid
Questão 41
Questão
Class 2 tRNA syntheses enzyme attach the amino acid to the 2'OH of the tRNA and are generally monomeric.
Responda
- True
- False
Questão 42
Questão
each aminoacyl tRNA synthetase attaches a single amino acid to only one tRNA which is know as isoaccepting tRNAs.
Responda
- True
- False
Questão 43
Questão
most organism have 20 different tRNA synthetase
Responda
- True
- False
Questão 44
Questão
tRNA structure that determine recognition by specific aminacyl tRNA synthetases?
Responda
-
acceptor stem and discriminator base
-
D loop
-
anticodon loop
-
variable loop
Questão 45
Questão
Why does aminoacyl-tRNA synthetase face a challenge in selecting the correct amino acid?
Responda
-
small size
-
side chains
-
similarity
Questão 46
Questão
There is more proofreading after the aminoacyl-tRNA synthetase has used its editing pocket to charge tRNAs with low accuracy.
Responda
- True
- False
Questão 47
Questão
when cysteinyl-tRNA ^cys converted to alanine-tRNA^ cys ( by reduction) and added to a cell free protein synthesizing system, alanine-tRNA^cys introduces alanines at the codons that are suppose to be cysteine. why?
Responda
-
ribosomes recognize tRNA not amino acid that its carrying
-
wrong tRNA has been incorporated
-
the tRNA is isoaccepting therefore can carry more than one amino acid
Questão 48
Questão
Eukaryotes can commence translation of the mRNA as it emerges from the RNA polymerase because the transcription machinery and the translation machinery are in the same compartment.
Responda
- True
- False
Questão 49
Questão
The ribosome is made up of large subunit which contains the [blank_start]peptidase transferase center[blank_end] and the small subunit that contains the [blank_start]decoding center[blank_end].
Responda
-
decoding center
-
peptidase transferase center
-
30S
-
50S
Questão 50
Questão
polysomes are
Responda
-
mRNA with multiple ribosomes
-
spaced 80 nt apart
-
polyribosomes
-
happen in eukaryotes
-
happen in prokaryotes
Questão 51
Questão
When small and large subunits undergo of the ribosome associate with each other and the mRNA, translate the target mRNA, then dissociate after each round of sythesis.
Responda
-
ribosome cycle
-
sedimentation by centrifugation
-
polysome
Questão 52
Questão
translation occurs
Responda
-
from 5' to 3'
-
from N terminal to C-terminal
-
by attaching new amino acid to the C-terminus of a growing polypeptide chain
Questão 53
Questão
substrate(s) for a round of amino acid addition are
Responda
-
2 charged species of tRNA
-
1 charged species of tRNA
Questão 54
Questão
The bond between the aminoacyl-tRNA and the amino acid is not broken during the formation of the next peptide bond.
Responda
- True
- False
Questão 55
Questão
What drives the peptide bond formation?
Responda
-
simultaneous hydrolysis of nucleoside triphosphate
-
breaking the high energy acyl bond that joins the growing polypeptide chain to the tRNA
Questão 56
Questão
ribosomal RNAs are represent the main component of the ribosome because
Responda
-
are located in the interior of the ribosome
-
essential for the peptidyl transferase reaction and binding the anticodon loop of tRNAs
-
are larger then proteins
-
protein stable rRNA by shielding negative charges of their sugar phosphate backbones
Questão 57
Questão
what are the three binding sites for tRNA on a ribosome
Responda
-
A site
-
D site
-
Enter site
-
P site
-
E site
Questão 58
Questão
peptidyl transferase center
Responda
-
formed by 20 nucleotides of 23s RNA
-
the 3'OH group of the tRNA in the P site is critical for activity and assist a concerted proton transfer
-
orients tRNAs in optimal proximity for peptidyltransferase rxn to occur
Questão 59
Questão
what allows only unpaired RNA to pass through the small and large subunit of the ribosome?
Responda
-
entry and amino channel
-
exit and adjacent channel
-
entry and exit channel
Questão 60
Questão
[blank_start]Entry[blank_end] channel is through the small subunit which is only wide enough to let unpaired mRNA through and too narrow for a [blank_start]secondary[blank_end] structure. Ensures that codons in mRNA will be exposed and available for pairing with the anticodon loops of tRNA.
Responda
-
Entry
-
secondary
Questão 61
Questão
the kink in the mRNA between two codons are included after ribosome translocation to not allow any entry of the mRNA
Responda
- True
- False
Questão 62
Questão
[blank_start]Exit[blank_end] channel lets nascent polypeptide through. Some secondary structures can form inside but some can't. But [blank_start]tertiary[blank_end] and quaternary structure will not be formed until after its exit the ribosome.
Responda
-
Exit
-
tertiary
Questão 63
Questão
Successful initiation in translation occurs when?
Responda
-
ribosome is recruited to the mRNA
-
ribosome placed over the start codon
-
charged tRNA placed into P site
-
tRNA goes through hydrolysis
Questão 64
Questão
translation initiation in prokaryotes is mostly done in the absence of the full ribosome
Responda
- True
- False
Questão 65
Questão
Specialized charged tRNA that binds directly to the P site and not the A site during initiation.
Responda
-
met-tRNA
-
initiator tRNA
-
charged tRNA
Questão 66
Questão
One of the three initiation factors, that binds to the small subunit and block its from reassociating with the large subunit or from binding charged tRNAs.
Responda
-
IF3
Questão 67
Questão
purple-one of the three initiation factors in prokaryotes, it is a GTAPase which interacts with IF 1, charged initiator tRNA, and the small subunit.
yellow-prevents tRNAs from binding to the portion of the small subunit that will become part of the A site.
Responda
-
IF 1
-
IF 4
-
IF 3
-
IF2
Questão 68
Questão
the last step in initiation is the 70s initiation complex, where fmet-tRNA, start codon, base pair which allows the small subunit to undergo a conformational change.
Responda
- True
- False
Questão 69
Questão
In eukaryotic initiation, the 43s pre-initiation complex
Responda
-
1A attaches at the exit site
-
Met-tRNA^met is bound to e1F3
-
EIF1,3,5 are bound to the exit site
-
the initiation factors attach to the 40s ribosome
Questão 70
Questão
recognition of eukaryotic mRNAs after 43S pre initiation complex,
Responda
-
recognition of 5' cap mediated by 3 subunits
-
recognition is mediated by a 3 subunit protein that specifically binds to RNA
-
unstructured mRNA recruits the 43S pre initiation complex to mRNA by eIF4F and eIF5
Questão 71
Questão
once the complex is assembled at the 5' end of the mRNA, they move along the 5'-3' direction by a process that ATP-dependent
Responda
-
eIF4F-associated RNA helices
-
finding the start codon
-
base pairing of the anticodon
Questão 72
Questão
The reason why the initiator tRNA must bind to the small subunit before it binds to the mRNA is because it is used in scanning by recognizing the start codon through base pairing between anticodon of tRNA and start codon.
Responda
- True
- False
Questão 73
Questão
The binding of the large subunit to the small subunit in eukaryotes
Responda
-
releases initiation factors by GTP hydrolysis
-
FMet-tRNA is placed in the P site of the 80s initiation complex
-
start codon and initiator tRNA in the P site is now ready to accept charged tRNAs
Questão 74
Questão
Poly-A-binding protein and eIF4G interact by the 5' and 3' end of the mRNA to
Responda
-
make mRNA linear
-
stabilize mRNA (exonucleases)
-
decrease efficiency of translation
-
helps recycling ribosomes
Questão 75
Questão
Exceptions to eukaryotic polypeptide being encoded by an open reading frame that starts with AUG?
Responda
-
internal ribosome entry sites
-
eIF3
-
uORF
Questão 76
Questão
eIF4G adaptor role when an mRNA is capped?
Responda
-
eIF4G directly binds to IRES
-
eIF4G binds to poly A tail
-
eIF4G serves as an adaptor between the pre initiation complex and the EIF4E bound to it
Questão 77
Questão
Elongation is very different in prokaryotes and eukaryotes.
Responda
- True
- False
Questão 78
Responda
-
translocation
Questão 79
Questão
When EF-Tu is bound to GDP and lacking any bound nucleotide it shows high affinity for aminoacyl-tRNAs.
Responda
- True
- False
Questão 80
Questão
What are one of the three mechanisms that contributes to the fidelity of codon recognition?
Responda
-
two adjacent adenine residues in 16S
-
ATP hydrolysis
Questão 81
Questão
Third mechanism in correct codon-anticodon incorporation is [blank_start]accommodation[blank_end], which is rotation of tRNA into the peptidyl transferase center.
Responda
-
accommodation
-
GTP hydrolysis
Questão 82
Questão
Reason why ribosome is a ribozyme?
Responda
-
23s RNA
-
proteins
-
aminoacyl-tRNA
Questão 83
Questão
23S rRNA catalyzes peptide bond formation by base pairing with the CCA variable loop of the tRNAs in the A and the P sites with help position alpha amino go of aminoacyl tRNA to attack carbonyl of growing peptide attached to peptidyl-tRNA.
Responda
- True
- False
Questão 84
Questão
[blank_start]EF-G[blank_end] is an elongation factor that completes translocation by binding to the ribosome's factor binding center with GTP.
Responda
-
EF-G
-
EF-Tu
Questão 85
Questão
[blank_start]molecular mimicry[blank_end] in which a protein takes on the appearance of a tRNA to facilitate association with the same binding site.
Responda
-
molecular mimicry
-
all elongation factor
Questão 86
Questão
Exchange of GDP for GTP for both EF-TU-GDP and EF-G-GDP are? ( in order)
Responda
-
GDP release and binds to new GTP, exchanging GDP for GTP by complex
-
exchanging GDP for GTP by complex, GDP release and binds to new GTP,
Questão 87
Questão
Eukaryotic factors analogous to EF-Tu ([blank_start]eEF1[blank_end]) and EF-G([blank_start]eEF2[blank_end]) are name differently but have similar function.
Responda
-
eEF1
-
EIF1A
-
eEF2
-
EF-Tu
Questão 88
Questão
how many molecules of ATP and GTP are used for peptide bond formation?
Responda
-
2 ATP and 1 GTP
-
2GTP and 1 ATP
-
3 ATP and 0 GTP
Questão 89
Questão
Termination of translation is done by
Responda
-
RF1: recognizes UGA
-
release factors
-
RF2: recognizes UGA
-
eRF1
Questão 90
Questão
the name of the codon on the release factor the recognizes a stop codon?
Responda
-
anticodon
-
peptide anticodon
-
GGQ
Questão 91
Questão
Class II release factor RF3,
Responda
-
has higher affinity for GDP than GTP
-
conformational change in ribosome, the class 1 RF stimulates GDP to GTP exchange
-
No class 1 RF, RF-3-GDP has high affinity for ribosome
Questão 92
Questão
RRF
Responda
-
ribosome recycling factor
-
mimics tRNA
-
works with EF-G and IF3
Questão 93
Questão
Puromycin is an aminoglycoside antibiotic which binds to the 16rRNA causing misreading of the genetic code
Responda
- True
- False
Questão 94
Questão
tetracycline is a polyketide, which block the p site.
Responda
- True
- False
Questão 95
Questão
puromycin
Responda
-
mimics aa-tRNA
-
used for cleaning purposes
Questão 96
Questão
SsrA
Responda
-
in prokaryotes
-
initiation factor
-
tmRNA (tRNA/mRNA
Questão 97
Responda
-
non-stop mediated decay
-
nonsense mediated mRNA decay
Questão 98
Responda
-
nonstop mediated decay
-
nonsense mediated mRNA decay
Questão 99
Questão
protein mediated regulation in bacteria
Responda
-
inhibition of 30s initiation complex binding
-
secondary structure of mRNA can inhibit translation initiation
Questão 100
Questão
riboswitches are
Responda
-
RNA sensors for regulation of translation
-
binding to its own mRNA
Questão 101
Questão
regulation of translation by small RNA (sRNA) in bacteria
Responda
-
eIF2
-
Hfq
Questão 102
Questão
initiation in eukaryotic translation is globally regulated by
Responda
-
rapamycin
-
eIF4G
-
elF4E-binding proteins
Questão 103
Questão
gene specific regulation of translation through cap sequestration in eukaryotes
Responda
- True
- False
Questão 104
Questão
Iron regulation is mediated by amino acids acting as sensor via steric hinderance
Responda
- True
- False
Questão 105
Questão
[blank_start]Translation[blank_end] of GCN4 is controlled by short upstream ORFs.
Responda
-
Translation
-
upregulation
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