Translation

Question 1

mRNA’a are decoded in the 5’ to 3’ direction, ____ codon at a time

Answer 1

one

Question 2

tRNA’s are _______ molecules with a common architecture which allow codon recognition and link _____ codons to specific ___________

Answer 2

adaptor, specific, amino acids

Question 3

________ _____ _____ allows some tRNA’s to recognize alternative codons

Answer 3

wobble base pairing

Question 4

linking an ____ ____ to a tRNA molecule requires specific _________ capable of reading the genetic code.

Answer 4

amino acid, enzymes

Question 5

the ______ is the molecular machine in charge of protein synthesis

Answer 5

ribosome

Question 6

the ______ polypeptide is the synthezied N term first

Answer 6

nascent

Question 7

the ribosome is ____ subunits joined together around _____ to make an active site.

Answer 7

two, mRNA

Question 8

tRNAs are a genetic ________ which assist in translation

Answer 8

dictionary

Question 9

mRNA is read ____ to ____

Answer 9

5’, 3’

Question 10

the core structure of the ribosome is formed by ________ _____.

Answer 10

ribosomal RNA

Question 11

peptidyl transferase center is in the ______ between the _______ of the ribosome.

Answer 11

cleft , subunits

Question 12

ribosomal proteins are on the surface but extend _____ into core rRNA structure to ________.

Answer 12

fingers, stabilize

Question 13

the mature mRNA contains the sequence of the ______ in genetic code

Answer 13

protein

Question 14

mRNA’s are decoded __ to __ direction in sets of ______ nonoverlapping nucleotides

Answer 14

5’, 3’, 3

Question 15

translation begins at an initiator _____ codon. (MET)

Answer 15

AUG

Question 16

frame shifting during translation is _______

Answer 16

rare

Question 17

tRNAs contain the _______ for the mRNA and are linked to the cognate _____ ______ at the acceptor stem

Answer 17

anticodon, amino acid

Question 18

anticodon loop basepairs with the _______

Answer 18

codon

Question 19

the amino acid is added to the 3’ _______ sequence - CCA

Answer 19

adaptor

Question 20

the nascent polypeptide chain the _____ terminus is made first and the __ terminus stays attached to the last tRNA. the chain emerges through ribosome _____ ______ which can protect 40 AA.

Answer 20

N, C, exit tunnel

Question 21

in peptidyl transferase rxn, the ____ attacks ester linkage of adajacent tRNA, activated peptidyl tRNA bond is maintained

Answer 21

amine

Question 22

protein folding and chaperone binding begins immediately upon emergance from ______ ______ _______

Answer 22

ribosome exit tunnel

Question 23

why is translation complicated when the peptide bond is a simple chemical reaction?

Answer 23

you aren’t making any peptide bond but the CORRECT peptide bond; information transfer with speed and high fidelity. so cells expend a lot of energy to get it correct.

Question 24

translational fidelity
- correct charging of ______ by tRNA synthetases
-codon dictated selection of matching ______ at the ribosome
-speed

Answer 24

tRNAS, tRNA

Question 25

mechansims of translational fidelity -tRNA synthetases -degeneracy of _____ + wobble position - monitoring of codon-anticodon _____ -________ coupling to irreversible hydrolysis steps- amplify signal of correct pairing -kinetic proofreading -ribosome quality control

Answer 25

code, basepairing, allosteric

Question 26

aminoacyl tRNA synthetases ____ the genetic code and ______ the right amino acid with the right tRNA

Answer 26

read, couple

Question 27

aminoacyl transferases perform ___ step coupling of AA to tRNAs. first is AA ______ then AA ______

Answer 27

two, activation, transfer

Question 28

amino acids are couple to tRNA's via high energy ______ bonds to the ______ of the ribose on the 3' adenosine

Answer 28

ester, 3'OH

Question 29

aminoacyl tRNA synthetases are highly ________ for their _______ and ______

Answer 29

specific, tRNA, amino acid

Question 30

error rate on tRNA selection is better than AA selection, why?

Answer 30

because there is a larger surface are meaning more bond discrimination

Question 31

double sieve mechanism is to ensure correct selection of _______ _______-

Answer 31

amino acid

Question 32

at active site, mostly correct amino acids are ______

Answer 32

charged

Question 33

at editing site, wrong amino acids are ______

Answer 33

removed

Question 34

degeneracy of genetic code contributes to robustness of information _______-

Answer 34

transfer

Question 35

like amino acids are encoded by like _______

Answer 35

codons

Question 36

mutations do not always lead to changes in _______ ______ level

Answer 36

amino acid

Question 37

wobble base pairing allows a single tRNA to recognize _______ codons

Answer 37

alternative

Question 38

inosine is a modified base with ______ base pairing capabilities

Answer 38

broader

Question 39

Inosine (I) can base pair with __, ___, ___.

Answer 39

C, U, A

Question 40

the small ribosome subunit _____ ________

Answer 40

binds mRNA

Question 41

the large ribosome subunit _______ the _______ ________ reaction

Answer 41

catalyzes, peptidyl transferase

Question 42

tRNA's bind in three sites, _________ , _________, ______

Answer 42

aminoacyl, peptidyl, exit (APE)

Question 43

__________ proceeds in steps: tRNA ______, peptide bond _______, large+small subunit translation.

Answer 43

elongation, binding, formation

Question 44

________ _____ around codon-anticodon basepairing of the first two bases in a codon ensures fidelity

Answer 44

induced fit

Question 45

hydrolysis of GTP by two elongation factors EF-Tu, EF-G ensures ________ accuracy

Answer 45

translation

Question 46

peptide bond formation is catalyzed by the peptidyl transferase ________ of the ribosome. catalysis by proximity and orientation. the energy for the reaction comes from reactivity of the high energy ester bond between ______ and ________.

Answer 46

center, tRNA, amino acid

Question 47

mRNA molecules are translated in cycles of _____ steps

Answer 47

four

Question 48

mRNA translation 1) tRNA binding at ___ site 2) peptide bond ______ 3) ______ subunit translocated to ___ site 4) ______ subunit translocated to ___ site 5) ____ is ejected at ___ site 6) newly bound charge ____ binds at ___ site

Answer 48

A formation large, P small, P tRNA, E tRNA, A

Question 49

tRNA's bind to the ribosome in a ternary complex with _____ and ______

Answer 49

EF-Tu, GTP

Question 50

correct basepairing of tRNA trigger release of ______

Answer 50

GDP

Question 51

incorrect basepared tRNA's preferentially _______-

Answer 51

disassociate

Question 52

correct codon-anticodon basepairing causes a __________ change that triggers GTP _______ in EF-Tu and disassociation

Answer 52

conformational, hydrolysis

Question 53

EF-Tu disassociation begins accommodation which is the postioning of AA next to each other in peptidyl transferase site. this will take _______ for incorrect bp matches and allows more time for __________

Answer 53

longer, disassociation

Question 54

induced fit is folding around _____ ______ that favors catalysis

Answer 54

base pair

Question 55

kinetic proofreading is an ________ step that happens faster for _______ basepairs, making _______ basepairs have more time to disassociate

Answer 55

irreversible, correct, incorrect

Question 56

GTP hydrolysis results in conformation changes in EF-G that force tRNA's and mRNA to move through the ribsome by a distance of ______ codon

Answer 56

one

Question 57

translocation of mRNA's and tRNA's through the ribosome is driven _______ by GTP _______-

Answer 57

forward, hydrolysis

Question 58

______ _______ are bound by protein release factors (not tRNA's)

Answer 58

stop codons

Question 59

release factors force _______ which release the peptide then causing disassociation of the ribosome

Answer 59

hydrolysis

Question 60

the same ______ can be translated by ________ ribosomes: polyribosomes

Answer 60

mRNA, multiple

Question 61

problems in translation lead to ribosome _________

Answer 61

stalling

Question 62

stalling can trigger pathways for ______ and _______ degradation ________ recycling stress ______

Answer 62

mRNA, protein, ribosome, response

Question 63

ribosome quality control is the research of identifying factors that recognize _________ ribosomes

Answer 63

stalled