Lecture 34

Question 1

what is the universal start codon

Answer 1

AUG - methionine

Question 2

3 stop codons

Answer 2

UAA, UAG, UGA

Question 3

how many codons are there

Answer 3

61

Question 4

how many tRNAs are there

Answer 4

32

Question 5

position 1 of anticodon dictates what

Answer 5

number of codons the tRNA can bind

Question 6

how many codons for A or C

Answer 6

1

Question 7

how many codons for U or G

Answer 7

2

Question 8

how many codons for inosinate

Answer 8

3

Question 9

wobble hypothesis

Answer 9

position 34 inosine may base pair with uridine, cytidine, adenosine

Question 10

what must happen to tRNA

Answer 10

must be activated

Question 11

tRNA activation catalyzed by

Answer 11

aminoacyl-tRNA synthtases

Question 12

aminoacyl-tRNA synthetases require what

Answer 12

2 ATP

Question 13

initiation of translation in bacteria requires what

Answer 13

30s subunit, mRNA, initiating fMet-tRNA, 3 initiation facts, GTP, 50S SU, Mg2+

Question 14

region of mRNA that guides the initiating AUG to its correct position

Answer 14

Shine Dalgarno sequence

Question 15

is shine dalgarno up or downstream from AUG

Answer 15

upstream

Question 16

inserts N-formyl-methionine at the amino terminal end

Answer 16

fMet-tRNA

Question 17

fMet-tRNA is added in response to wha t

Answer 17

AUG initiation codon

Question 18

inserts methionine in interior positions

Answer 18

Met-tRNA

Question 19

added in response to the interior AUG codons

Answer 19

Met-tRNA

Question 20

bacterial ribosome, what Subunits

Answer 20

50s and 30s -> 70s

Question 21

eukaryotic ribosome, what subunits

Answer 21

60s and 40s -> 80s

Question 22

site where amino acids are added to the growing chain

Answer 22

peptide site (p site)

Question 22

site where incoming aminoacyl-tRNAs bind

Answer 22

aminoacyl site (A site)

Question 23

only site where fMet-tRNA can bind

Answer 23

P site

Question 24

binds uncharged tRNAs

Answer 24

exit site

Question 25

eukaryotic mRNAs are bound to

Answer 25

ribosome

Question 26

eukaryotic cells have how many initiation factors

Answer 26

12

Question 27

in eukaryotic cells, is there shine dalgarno seq

Answer 27

no

Question 28

what is Met bound to in eukaryotic cells

Answer 28

initiation tRNA, not fMet

Question 29

do eukaryotic cells have an exit site

Answer 29

no

Question 30

more or less init factors in eukaryotic

Answer 30

more

Question 31

elongation requires

Answer 31

initiation complex, aminoacyl-tRNAs, elongation factors, 2 GTP

Question 32

what are the elongation factors

Answer 32

Tu, Ts, and G

Question 32

where do uncharged tRNA leave directly from in eukaryotic

Answer 32

directly from p site

Question 33

in bacteria, release factor and energy from GTP hydrolysis aid in what

Answer 33

ribosome dissociation

Question 34

promotres dissociation of the tRNA and release factor

Answer 34

IF3

Question 35

IF3 promotes dissociation of what

Answer 35

tRNA and release factor

Question 36

inhibitory antibiotic that binds to the A site and terminates polypeptide synthesis

Answer 36

puromycin

Question 37

puromycin structure similar to what

Answer 37

3’ end of aminoacyl-tRNA

Question 38

inhibit bacterial protein by blocking the A site

Answer 38

tetracyclines