DNA 5

Question 1

protein synthesis occurs at the

Answer 1

ribosome

Question 2

the ribosome is a

Answer 2

complex formed of rRNA and several proteins

Question 3

what must the ribosome hold to make a polypeptide

Answer 3

mRNA and tRNA

Question 4

the details of the molecular recognition are key to making translation

Answer 4

probable

Question 5

recognition of tRNA happens at

Answer 5

the decoding site
A site

Question 6

catalysis happens at the

Answer 6

transferase center
p site

Question 7

last spot of translation complex

Answer 7

exit
e site

Question 8

ribosome total weight

Answer 8

70s

Question 9

two segments of ribosome

Answer 9

30S and 50S

Question 10

the 50S subunit contains

Answer 10

23S RNA
5S RNA
34 proteins

Question 11

the 30S subunit contains

Answer 11

16S RNA
21 proteins

Question 12

rRNA in the 90’s

Answer 12

shown with 50 A by electron microscopy

Question 13

the secondary structure of such large RNAs can be

Answer 13

elaborate

Question 14

which subunits are on the top and bottom

Answer 14

30S bottom
50S top

Question 15

the 30S subunit holds

Answer 15

the mRNA

Question 16

the 50S subunit catalyzes

Answer 16

the peptide bond formation

Question 17

translocation and successive binding of the next tRNA are

Answer 17

GTP dependent

Question 18

three sites for tRNA binding

Answer 18

A
P
E

Question 19

as the peptide is made it can either

Answer 19

coil into an alpha helix or wait to be picked up by a chaperonin

Question 20

the release factor signals

Answer 20

the end of the protein synthesis

Question 21

first the individual subunits must recognize and

Answer 21

bind

Question 22

release of the complex follows the stop codon and completion. this allows for

Answer 22

ribosome recycling and energy conservation

Question 23

to initiate complexation the tRNA must be… with its correct amino acids

Answer 23

charged

Question 24

tRNA is charged with

Answer 24

a tRNA synthetase

Question 25

tRNA synthetases are specific to

Answer 25

each amino acid which provides a level of proof reading

Question 26

after charging of a tRNA what can occur?

Answer 26

formylation

Question 27

first amino acid added

Answer 27

formyl methionine

Question 28

formyl methionine initiates

Answer 28

complex formation and starts the chain growth

Question 29

the usual lactam condensation is catalyzed at

Answer 29

the active site of the ribosome the peptidyl transferase site

Question 30

when were the first 3 sites shown on EM work

Answer 30

1999 at 7.5 A shows the three sites from the 30S and 50S POV

Question 31

the tRNA must fit in a specific pocket of the

Answer 31

70S complex

Question 32

the ribosome atomic structure was solved by

Answer 32

x-ray diffraction on 2000 to 2.7 A

Question 33

each of the 30S and 50S subunits have an interesting set of

Answer 33

domain structure

Question 34

the domain structures are specialized for

Answer 34

holding and release of tRNA

Question 35

how many proteins are in the ribosome in prokaryotes

Answer 35

55

Question 36

how many proteins are in the ribosome in eukaryotes

Answer 36

79-80

Question 37

proteins in the ribosome are

Answer 37

highly conserved across life forms and require chaperones

Question 38

how many subunits are conserved between life forms

Answer 38

15

Question 38

absense of some subunits in lower life forms shows evolutionary additions usually on the

Answer 38

outside

Question 39

the proteins in the ribosome have different tertiary structures than

Answer 39

globular proteins

Question 40

proteins in the ribosome have long strands that reach deeply into the rRNA making

Answer 40

favorable contacts

Question 41

there are no proteins in

Answer 41

the peptidyl transferase center

Question 42

the ribosome is a

Answer 42

ribozyme

Question 43

under stress conditions such as heat or antibiotics

Answer 43

ribosomes stall leading to halted protein synthesis

Question 44

to remobilize ribosomes bacteria use

Answer 44

rescue factors such as HflXr, a GTPase, that catalyzes the dissociation of translational inactive ribosomes into individual subunits

Question 45

bacterial chromosomes spend a considerable amount of time in an inactive state known as

Answer 45

ribosome hibernation

Question 46

during ribosome hibernation

Answer 46

the subunits dissociate and bind protein hibernation factors

Question 47

some hibernation factors occupy

Answer 47

drug binding sites, antibiotics and recycling affect each other