Kandpal-Translation Initiation

Question 1

where do ribosomes bind?

Answer 1

at a conserved 5’ untranslated region (UTR) 10 bases upstream of AUG

Question 2

what is the name of where the ribosome binds?

Answer 2

shine-dalgarno sequence (AGGAGGU)

Question 3

what does the initiator tRNA contain?

Answer 3

N-formyl-methionine (fMet)

Question 4

what type of immune response remembers previous encounter with pathogens?

Answer 4

adaptive immune system

Question 5

what type of immune response relies on proteins and phagocytic cells to recognize pathogens?

Answer 5

innate immunity

Question 6

what type of peptide does the body use to distinguish self from non-self?

Answer 6

formylmethionine containing peptides

Question 7

what initiation factors keep the 30S subunit free?

Answer 7

IF-1 and IF-3

Question 8

what initiation factor blocks the A site?

Answer 8

IF-1

Question 9

what initiation factor is important for binding mRNA?

Answer 9

IF-3

Question 10

what factor allows for tRNA to bind to 30S subunit?

Answer 10

IF-2

Question 11

when will the 50S and 30S subunit combine?

Answer 11

when IFs are released

Question 12

what enters the partial P site on 30S subunit bound to mRNA?

Answer 12

fMet-tRNA

Question 13

what part of the EF-Tu (elongation factor) complex enters the A site?

Answer 13

alpha,alpha-tRNA

Question 14

where the is fmet from the initiator-tRNA transferred too?

Answer 14

to the aminoacyl-tRNA in the A site

Question 15

what part of the ribozyme contains the peptidyl transferase activity?

Answer 15

23 rRNA of the large subunit

Question 16

what causes the exit of the tRNA from P site?

Answer 16

GTP binding elongation factor EF-G

Question 17

do tRNA’s recognize stop codons?

Answer 17

nope

Question 18

what events do release factors trigger?

Answer 18

cleavage of polypeptide from tRNA, release of polypeptide and mRNA and dissociation of ribosome subunits

Question 19

how do antibiotics inhibit protein synthesis?

Answer 19

they bind selectively to various sites on ribosomes

Question 20

what does choloramphenicol do in bacteria?

Answer 20

inhibits peptidyl transferase in prokaryotes (50S)

Question 21

what does streptomycin do?

Answer 21

inhibits initiation to elongation transition (30S)

Question 22

what does erythromycin do in bacteria?

Answer 22

inhibits translocation by binding to 50S ribosome

Question 23

what does tetracycline do in bacteria?

Answer 23

prevents aminoacyl-tRNA binding to A site (30S)

Question 24

in eukaryotic translation, what is unique about the tRNA that is used to initiate synthesis?

Answer 24

contains its own aminoacyl tRNA synthetase

Question 25

in eukaryotes does f-Met still serve a function in the tRNA?

Answer 25

no. only Met can interact with eIF2 not f-Met

Question 26

what is needed to help the intiation complex unwind and scan the mRNA?

Answer 26

ATP

Question 27

what does eIF4 bind too?

Answer 27

“cap”, Poly(A), mRNA, 40S ribosomal subunit

Question 28

does eIF4 have helicase activity?

Answer 28

yes to unwind the secondary structure

Question 29

when will translation take place in the eukaryotes?

Answer 29

when the intiation complex moves from the 5’-end cap to the first AUG

Question 30

what initiation complex is formed in eukaryotes when 40S initiation complex joins the 60S subunit?

Answer 30

80S ribosome

Question 31

what allows for elongation in eukaryotes?

Answer 31

GTP binding EF1-alpha

Question 32

hydrolysis of what is necessary for translocation to take place (move from A site to P site)?

Answer 32

EF2-GTP