translation Flashcards
(99 cards)
1
Q
process of synthesizing proteins from mRNA
A
translation
2
Q
T/F Mature mRNA has a 5’ methylguanosine cap and a 3’ poly A tail.
A
T
3
Q
sequence of three nucleotides that specifies an amino acid or termination signal during translation
A
codons
4
Q
4 nucleotides in RNA
A
Adenine
Guanine
Uracil
Cytosine
5
Q
Total Number of Codons: __
Number of Codons coding for AA: __
Nonsense Codons: __
A
64
61
3
6
Q
3 codons serving as termination signals
A
UAG
UGA
UAA
7
Q
direction of translation in mRNA
A
5’ to 3’
8
Q
GENETIC CODE CHARACTERISTIC
Translation occurs continuously from end to end
A
COMMA LESS
9
Q
GENETIC CODE CHARACTERISTIC
tRNA is read through every codon
A
COMMA LESS
10
Q
GENETIC CODE CHARACTERISTICS
If two nucleotides occur between each codon, they are not skipped
A
comma less
11
Q
GENETIC CODE CHARACTERISTICS
The ribosomes will always translate the mRNA by the codons and assign 1 amino acid per codon
A
Non Overlapping
12
Q
another term for redundancy in the genetic code
A
Degenerate
13
Q
GENETIC CODE CHARACTERISTICS
multiple codons code for the same amino acid
A
Redundant
14
Q
two codons exempted to the rule of redundancy; only one codon codes for these amino acids
A
AUG (Methionine) and UGG (Tryptophan)
15
Q
phenomenon that occurs in redundant codons which provides flexibility in base pairing & decreases mutation rates
A
Wobble Effect
16
Q
In the Wobble Effect, which nucleotide in the anticodon sequence is flexible and can bind with multiple bases in the codon?
A
Inosine
17
Q
decreases the mutation rate by allowing flexibility in codon-anticodon pairing (changes in the first nucleotide of codon do not necessarily change the AA produced)
A
Wobble Effect
18
Q
three nucleotides that inosine can bind to due to its flexibility in the Wobble Effect
A
Adenine, Uracil, and Cytosine
19
Q
nucleotide that provides flexibility, allowing for the codon change without altering the amino acid; maintains protein integrity.
A
Inosine
20
Q
T/F: Redundant codons mean that one amino acid is coded by more than one codon sequence.
A
T
21
Q
T/F AUG and UGG are examples of codons that follow the redundancy rule.
A
F
22
Q
T/F: In the Wobble Effect, inosine can bind to Guanine
A
F (A, U, C only)
23
Q
T/F
Errors in DNA replication or transcription will not affect the structure or function of the final protein.
A
F - leads to abnormally structured and functional proteins
24
Q
T/F
If something goes wrong in DNA replication, it can lead to mutations that are passed on through transcription and ultimately affect protein structure and function
A
T
25
number of nucleotides that make up a prototype tRNA molecule according to Craig
75-94 nucleotides
26
5’ end is attached to the _____ group while the 3’ end has the ______ functional group
Phosphate (PO4); Hydroxyl (-OH)
27
tail at the 3' end of tRNA, which binds to amino acids
CCA tail
28
acts as the amino acid domain where amino acids bind, giving tRNA the ability to carry amino acids
CCA tail
29
enables the tRNA to tether to the ribosome so that it would not wobble around as the translation goes on.
T-arm (T-loop)
30
T-arm contains modified nitrogenous bases in the form of ____ and also ____
ribothymidine (T) & pseudouridine (U)
31
enables aminoacyl-tRNA synthetase to recognize the tRNA molecule and helps in the correct binding of amino acids to the tRNA.
D- arm
32
D-arm or D-loop as it contains modified nitrogenous bases which is __
dihydrouridine
33
contains the anticodon sequence that pairs with the corresponding codon on mRNA, facilitating accurate translation
anticodon loop
34
which sequence of nucleotides makes up the anticodon loop
34th to 36th nucleotides
35
T/F The D-arm of tRNA helps tRNA recognize the correct mRNA codon
F (helps aminoacyl-tRNA synthetase recognize the tRNA molecule)
36
T/F The anticodon loop of tRNA is responsible for binding the correct amino acid.
F (CCA tail; anticodon loop - contains anticodon seq pairing w mrna codons)
37
OOO: Recognition of tRNA molecule by aminoacyl-tRNA synthetase
A) D-arm
B) Anticodon loop
C) T-arm
D) CCA tail
CCA tail - primarily for amino acid attachment, not recognition
38
sequence of the anticodon for the start codon
UAC
39
Sequence: Arrange the following steps of tRNA charging
1) Formation of S-adenosylmethionine
2) Cleavage of pyrophosphate (PP) from ATP
3) Binding of methionine to AMP
4) Charging of tRNA with methionine
2 - 3 - 1 - 4
40
T/F tRNA on its own carries amino acids before charging.
False - tRNA must be charged by aminoacyl-tRNA synthetase first to carry AA
41
OOO: Function directly in the charging of tRNA
A) ATP
B) Aminoacyl AMP
C) CCA tail
D) Ribosome
D) Ribosome
42
enzyme that charges tRNA with its corresponding amino acid is ______
Aminoacyl-tRNA synthetase
43
generic name for a molecule that consists of a nucleoside monophosphate carrying an amino acid, typically after the charging process
Amino Acyl AMP
44
T/F During tRNA charging, the carboxyl end of the amino acid binds to the hydroxyl group of the CCA tail, releasing AMP in the process.
T
45
the molecular configuration of ______ enables it to check that the anticodon on tRNA corresponds to the amino acid it carries.
Aminoacyl-tRNA synthetase
46
ensures that the correct amino acid is attached to the tRNA during charging
Aminoacyl-tRNA synthetase
47
two subunits present in both prokaryotic and eukaryotic ribosomes
Large Subunits and Small Subunits
48
T/F: In nature, eukaryotic ribosomes often sit side-by-side with prokaryotic ribosomes to interact with mRNA.
False - does not occur
49
Both eukaryotic and prokaryotic ribosomes are composed of ________ and ________
Ribosomal RNA and proteins
50
primary difference between eukaryotic and prokaryotic ribosomes
Size
51
T/F Ribosomes are only composed of ribosomal RNA
F - ribosomal RNA and proteins
52
OOO: Inhibit the 30S subunit of the ribosome
Aminoglycosides, Tetracyclines, Erythromycin, Glycylcycline-tigecycline
Erythromycin - inhibits the 50S subunit
53
________ are antibiotics that inhibits the 50S subunit of the prokaryotic ribosome (list)
Erythromycin, clindamycin, Chloramphenicol, Oxazolidinone-linezolid, Streptogramin-DQ
54
T/F: Clindamycin and Chloramphenicol inhibit the 30S subunit of the prokaryotic ribosome.
F - inhibit the 50S subunit
55
three phases of translation
Initiation, Chain Elongation, Chain Termination
56
T/F the Shine-Dalgarno sequence is a pyrimidine-rich sequence that helps the ribosome bind to mRNA in prokaryotes
False - purine-rich
57
The Shine-Dalgarno sequence starts at the _________ end of mRNA in prokaryotic cells.
5’ end
58
The Shine-Dalgarno sequence is represented by the sequence ________
GGAGGU
59
binds to the Shine-Dalgarno sequence in prokaryotic cells, signaling the start of translation
small ribosomal subunit (30S), aided by Initiation Factor-3 (IF-3)
60
T/F Initiation Factor-3 (IF-3) strengthens the binding of the large ribosomal subunit to the mRNA to start the translation process in prokaryotes.
F - IF-3 prevents premature binding of the large ribosomal subunit to the small ribosomal subunit
61
Initiation Factor-2 (IF-2) binds to tRNA and carries ________
GTP
62
OOO: Binding of the 30S ribosomal subunit during prokaryotic initiation
A) Initiation Factor-1
B) Initiation Factor-2
C) Initiation Factor-3
D) Initiation Factor-4
D
63
what happens to GTP during the initiation of translation in prokaryotic cells
broken down into GDP and inorganic phosphate, releasing energy
64
the tRNA molecule that binds to the start codon in prokaryotic translation carries ________.
n-formylmethionine
65
T/F The large ribosomal subunit requires initiation factors after it binds to the initiation complex.
F - large ribosomal subunit does not need initiation factors after binding
66
components of the 43S preinitiation complex in eukaryotic translation
tRNA
methionine
GTP
eukaryotic initiation factors
40S ribosomal subunit
67
T/F Eukaryotic initiation factor 2 (eIF2) binds tRNA that carries methionine & GTP during the initiation phase.
T
68
The 43S subunit and eukaryotic initiation factors make up the ________ preinitiation complex.
48S
69
primary energy source for the formation of the preinitiation complex in eukaryotic cells?
GTP
70
Sequence Question: Eukaryotic translation initiation
1 Formation of 43S preinitiation complex
2 Binding of eukaryotic initiation factors to the 40S ribosomal subunit
3 Breakdown of GTP into GDP and inorganic phosphate
4 Large ribosomal subunit binds to the mRNA
5 tRNA carrying methionine and GTP binds to the 40S subunit
2 1 5 3 4
71
Select All That Apply: Roles of eukaryotic initiation factors during translation initiation
A) Bind to the 40S ribosomal subunit
B) Carry the amino acid
C) Stabilize the mRNA binding
D) Facilitate the breakdown of GTP
A, C, D (B - tRNA carries the amino acid)
72
T/F Eukaryotic initiation factors bind to the 50S ribosomal subunit during the formation of the 43S preinitiation complex.
F (Eukaryotic initiation factors bind to the 40S ribosomal subunit.)
73
The ________ ribosomal subunit packages the mRNA molecule from the 5' to the 3' prime end during the initiation of translation in eukaryotic cells.
large
74
three sites found in the large ribosomal subunit during translation
Aminoacyl site (A-site), Peptidyl site (P-site), Exit site (E-site)
75
at the start of elongation, the ribosomal subunits sandwich the mRNA molecule from the _______ to _______ end.
5’ to 3’
76
site on the ribosome that contains the tRNA that carries methionine at the start of elongation
P-site
77
The _________ site is the arrival site for the next tRNA molecule, which requires the assistance of __________ to enter.
A-site, Eukaryotic Elongation Factor 1 (eEF1)
78
T/F Eukaryotic Elongation Factor 1 (eEF1) brings tRNA to bind to the AUA codon in the mRNA within the large ribosomal subunit.
T
79
what does the large ribosomal subunit break down to allow eEF1 to bring tRNA into the A-site
GTP into GDP and inorganic phosphate
80
once two amino acids, methionine, and isoleucine, are closely seated together, a ________ bond is formed between them.
Peptide bond
81
OOO: Elongation phase
1 Peptide bond formation
2 eEFG2 aids translocation
3 tRNA carries stop codon
4 GTP is broken down into GDP and inorganic phosphate
tRNA carries stop codon - trna never carries stop codon, just amino acids
82
T/F Peptidyl transferase removes methionine from tRNA and only exists in the P-site of the ribosome.
F - A site
83
__________ is required for translocation to occur, carrying with it a GTP molecule that is broken down for energy.
eEFG2
84
signals the termination of translation in the ribosome
stop codon (UAA, UAG, or UGA) in the RNA molecule
85
during termination, the _________ factor binds to the stop codon in the A-site and stops the translation process
Release factor
86
T/F release factor in the A-site prevents the peptide from being released and halts translation
F - helps release the peptide from the P-site
87
After translation termination, the peptide is released and can be incorporated into the ___________, secreted into the extracellular fluid, or used elsewhere.
Cell membrane
88
types of proteins are synthesized by free ribosomes
Cytosolic proteins, Nuclear proteins, Mitochondrial enzymes, Peroxisomal enzymes
89
The rough endoplasmic reticulum synthesizes proteins such as ________, ________, and ________ proteins.
Lysosomal, secreted, membrane
90
Select All That Apply: Proteins Synthesized by Free Ribosomes
Membrane Proteins
Cytosolic proteins
Meroxisomal Enzymes
Secreted proteins
Nuclear proteins
Mitochondrial enzymes
Lysosomal Proteins
Cytosolic proteins
Nuclear proteins
Mitochondrial enzymes
Meroxisomal enzymes
91
series of 16-30 amino acid residues recognized by the Signal Recognition Particle (SRP) to direct the ribosome to the rough ER.
Signal Sequence
92
T/F the Signal Recognition Particle (SRP) binds to the ribosome and polypeptide complex to direct it to the rough ER membrane.
t
93
The _________ binds the ribosome and polypeptide complex to the ER membrane, and the _________ opens the translocon to allow the polypeptide to enter the ER lumen.
Signal Recognition Particle Receptor (SRPR), 2 GDP
94
Sequence Question: Protein translocation
1 SRP drags the ribosome-polypeptide complex to the ER membrane
2 Signal Peptidase cuts off the signal sequence
3 The translocon opens
4 SRP binds to the Signal Sequence
5 Peptide is released into the lumen of the rough ER
4 1 3 2 5
95
T/F The Signal Peptidase enzyme cuts off the signal sequence and releases the growing peptide into the lumen of the rough ER.
T
96
after the Signal Peptidase cuts off the signal sequence, the polypeptide is released into the _________ of the rough ER, where it will be further processed or secreted.
lumen
97
T/f once the signal sequence is cleaved, the protein will either be secreted into the extracellular fluid, become part of a membrane, or become a lysosomal protein.
t
98
Sequence: Aminoacyl tRNA synthetase's function
1 Checks the anticodon of tRNA
2 Recognizes the D-arm of tRNA
3 Holds the aminoacyl AMP molecule
4 Attaches the amino acid to the CCA tail
2 3 1 4
99
Sequence Question: Elongation process in protein synthesis
1 Eukaryotic elongation factor 1 (eEF1) brings tRNA to the A-site to bind to mRNA.
2 Methionine and Isoleucine form a peptide bond.
3 GTP is broken down into GDP and inorganic phosphate to provide energy for translocation.
4 Translocation occurs, moving the tRNA from the A-site to the P-site.
1 3 2 4
