Deck 40: The Mechanism of Protein Synthesis

Question 1

Initiation, elongation, and termination all require factors that are members of the __________________ family.

Answer 1

G-protein

Question 2

Proteins are synthesized in the __________________ direction.

Answer 2

N → C, or amino to carboxyl

Question 3

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) initiation factors
b) ATP
c) ricin
d) one
e) Shine-Dalgarno
f) elongation factor Tu
g) polysome
h) two
i) kanamycin
j) release factor
k) N-formylmethionine
l) signal sequence
m) GTP
The _______________ proteins recognize UAA, UAG, and UGA codons.

Answer 3

j

Question 4

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) initiation factors
b) ATP
c) ricin
d) one
e) Shine-Dalgarno
f) elongation factor Tu
g) polysome
h) two
i) kanamycin
j) release factor
k) N-formylmethionine
l) signal sequence
m) GTP
_______________ include(s) IF1, IF2, and IF3 in prokaryotes.

Question 5

The signal sequence that marks a protein for translocation across the endoplasmic reticulum membrane is located near the __________________ end of the protein.

Question 6

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) initiation factors
b) ATP
c) ricin
d) one
e) Shine-Dalgarno
f) elongation factor Tu
g) polysome
h) two
i) kanamycin
j) release factor
k) N-formylmethionine
l) signal sequence
m) GTP
The biomolecule _______________ delivers the aminoacyl-tRNA to the "A site" in E. coli.

Question 7

Release factors function by allowing __________________ to attack the ester linkage between tRNA and amino acid.

Question 8

In a ribosome, A stands for __________________ and P stands for __________________.

Question 9

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) initiation factors
b) ATP
c) ricin
d) one
e) Shine-Dalgarno
f) elongation factor Tu
g) polysome
h) two
i) kanamycin
j) release factor
k) N-formylmethionine
l) signal sequence
m) GTP
The protein _______________ is toxic because it hydrolyzes a critical adenine base from the 28S RNA molecule of eukaryotes.

Question 10

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) initiation factors
b) ATP
c) ricin
d) one
e) Shine-Dalgarno
f) elongation factor Tu
g) polysome
h) two
i) kanamycin
j) release factor
k) N-formylmethionine
l) signal sequence
m) GTP
_______________ inhibits the interaction between tRNA and 16S rRNA

Question 11

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) initiation factors
b) ATP
c) ricin
d) one
e) Shine-Dalgarno
f) elongation factor Tu
g) polysome
h) two
i) kanamycin
j) release factor
k) N-formylmethionine
l) signal sequence
m) GTP
_______________ is the first amino acid in bacteria and typically is chemically modified.

Question 12

GTP binds to the __________________ protein in the translocation mechanism.

Question 13

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) initiation factors
b) ATP
c) ricin
d) one
e) Shine-Dalgarno
f) elongation factor Tu
g) polysome
h) two
i) kanamycin
j) release factor
k) N-formylmethionine
l) signal sequence
m) GTP
EF-G translocase proteins use the energy of _______________ hydrolysis.

Question 14

The first amino acid in bacterial proteins is __________________.

Question 15

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) initiation factors
b) ATP
c) ricin
d) one
e) Shine-Dalgarno
f) elongation factor Tu
g) polysome
h) two
i) kanamycin
j) release factor
k) N-formylmethionine
l) signal sequence
m) GTP
_______________ is a sequence of 9-12 hydrophobic amino acid residues, sometimes containing positively charged amino acids.

Question 16

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) initiation factors
b) ATP
c) ricin
d) one
e) Shine-Dalgarno
f) elongation factor Tu
g) polysome
h) two
i) kanamycin
j) release factor
k) N-formylmethionine
l) signal sequence
m) GTP
The sequence that interacts with a complementary sequence on the 3` end of the 16S rRNA is _______________.

Question 17

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) initiation factors
b) ATP
c) ricin
d) one
e) Shine-Dalgarno
f) elongation factor Tu
g) polysome
h) two
i) kanamycin
j) release factor
k) N-formylmethionine
l) signal sequence
m) GTP
How many release factors do eukaryotes have?

Question 18

mRNA that codes for more than one protein is considered __________________.

Question 19

In E. coli, the signal sequence that properly aligns the initiation codon in the P site is called the __________________ sequence.

Question 20

After the peptide bond forms, the mRNA and tRNA are __________________, or moved, a distance of one codon.

Question 21

What is the direction of translation of mRNA?

A) bidirectional
B) 5` → 3`
C) 3` → 5`
D) All of the above.
E) None of the above.

Question 22

What is an iron response element?

Question 23

What proteins are involved in the circularization of eukaryotic mRNA?

Question 24

Ricin is made from castor beans and is a strong toxin which:

A) removes an adenine from 28S rRNA.
B) glycosylates tRNA.
C) inhibits protein synthesis initiation.
D) blocks the A binding site.
E) coats the mRNA.

Question 25

What is the order of the tRNA binding sites on the 70S ribosome with respect to the 5′ → 3′ direction of the mRNA?

A) E P A
B) P A E
C) A E P
D) P E A
E) E A P

Question 26

Describe RNAi.

Question 27

Signals that define the beginning and end of protein synthesis are contained in:

A) rRNA.
B) tRNA.
C) mRNA.
D) the ribosome.
E) protein.

Question 28

Eukaryotic mRNA is:

A) linear.
B) circular.
C) modified only at the ribose.
D) discontinuously translated.
E) None of the above.

Question 29

Can a protein fully translated and released from a ribosome enter the mitochondria or ER lumen?

Question 30

What is the final destination of proteins directed to the secretory pathway?

Question 31

In vanishing white matter disease, nerve cells disappear due to:

A) phagocytosis of living cells.
B) an autoimmune result of mutations in mRNA.
C) mutation in release factors.
D) mutations in initiation factor 2.
E) mutations in the tRNA charging mechanism.

Question 32

Eukaryotic and prokaryotic translation differs primarily in which step?

A) initiation
B) elongation
C) termination
D) All of the above.
E) None of the above.

Question 33

Describe the subunits of E. coli ribosomes.

Question 34

What factor(s) is (are) necessary for the correct placement of the mRNA and initiating tRNA on the ribosome?

A) IF1
B) IF2
C) IF3
D) A and B
E) A, B, and C

Question 35

What is the function of RF1?

Question 36

Which of the following is/are required for the initiation of protein synthesis in prokaryotes?

A) mRNA
B) the 30S subunit
C) fMet-tRNAf
D) GTP
E) All of the above.

Question 37

What is the mechanism of action of the A fragment of diphtheria toxin?

A) binding the 60S subunit
B) cleaving tRNA
C) the chemical modification of EF2
D) All of the above.
E) None of the above.

Question 38

Which of the following E. coli proteins is responsible for translocation of the mRNA as a result of a conformation change due to the hydrolysis of GTP?

A) RRF
B) EF-Tu
C) EF-G
D) Shine-Delgarno
E) None of the above.

Question 39

Chloramphenicol acts by:

A) binding to the peptidase cell-wall enzyme.
B) inhibiting peptidyl transferase activity.
C) inhibiting protein synthesis.
D) binding to fMET tRNA.
E) changing the shape of the mRNA.

Question 40

What are the names for the tRNA binding sites on the ribosome?

Question 41

What is the first step in the elongation cycle?

Question 42

What role does the amino acid itself play in the accurate placement of the charged tRNA at the codon?

Question 43

How does puromycin inhibit protein synthesis?

Question 44

What is the role of the translocon in protein synthesis?