Genetic Code and Protein Synthesis

Question 1

code words that are 3 bases long can specify ____ amino acids

Answer 1

64

Question 2

what is the start codon?

Answer 2

AUG

Question 3

what are the 3 stop codons?

Answer 3

UAA, UAG, UGA

Question 4

what codon is used the most in e coli?

Answer 4

CUG

Question 5

what codon is used the least in coli?

Answer 5

CUA

Question 6

what codon is used the most in humans?

Answer 6

CUG

Question 7

what codon is used the least in humans?

Answer 7

UUA

Question 8

___ out of the 64 amino acids specify amino acids

Answer 8

61

Question 9

what two amino acids are not coded by more than one sequence?

Answer 9

MET, TRP

Question 10

proteins are synthesized at the ____

Answer 10

ribosome

Question 11

prokaryotes are know as the ____S ribosomes

Answer 11

70

Question 12

eukaryotes are known as the ___S ribosomes

Answer 12

80

Question 13

what are the two parts of the prokaryotic ribosomes?

Answer 13

30S, 50S

Question 14

what are the two parts of the eukaryotic ribosomes?

Answer 14

40S, 60S

Question 15

a prokaryote can contain ____ ribosomes and a eukaryote can contain _____

Answer 15

20,000, 200,000

Question 16

what percent rRNA is the small pro subunit?

Answer 16

60

Question 17

what percent rRNA is the large pro subunit?

Answer 17

70

Question 18

what percent rRNA is the small euk subunit?

Answer 18

50

Question 19

what percent rRNA is the large euk subunit?

Answer 19

65

Question 20

what is the purpose of the gap between the ribosomal subunits?

Answer 20

mRNA goes through, RNA, growing protein chain

Question 21

where does the new amino acid bind to the ribosome?

Answer 21

A site

Question 22

at what site does the growing polypeptide growing?

Answer 22

P site

Question 23

at what site is the exit site for tRNA

Answer 23

E site

Question 24

what holds the growing chain to the P site?

Answer 24

the anticodon and tRNA

Question 25

pro: EF-Tu

Answer 25

eEf1(alpha)

Question 26

pro: EF-Ts

Answer 26

eEF1(beta)(gamma)

Question 27

pro: EF-G

Answer 27

eEF2

Question 28

what is the eukaryotic release factor?

Answer 28

eRF1

Question 29

what are the prokaryotic release factors?

Answer 29

RF-1, RF-2, RF-3

Question 30

initiation begins with the binding of ____ and the ___ _____ to the 30S ribosomal subunit

Answer 30

mRNA, initiator tRNA

Question 31

all other parts of the growing chain attach to the ___ site except for the initiator, which attaches to the ___ site

Answer 31

A, P

Question 32

what happens to GTP during initiation?

Answer 32

breaks down into GDP

Question 33

what it the anticodon sequence of f-met-tRNA?

Answer 33

5'CAU3'

Question 34

during peptide chain elongation, the first stage is the binding of a new ______ to the A site

Answer 34

aminoacyl-tRNA

Question 35

what elongation factor brings about the binding of a new aminoacyl-tRNA to the A Site?

Answer 35

EF-Tu

Question 36

what elongation factor recycles EF-Tu after it binds an aminoacyl-tRNA?

Answer 36

EF-Ts

Question 37

the ____ _____ activity is not due to a protein enzyme, but is due to an RNA enzyme activity of the peptidyl transferase center of the 23S rRNA and the 50S subunit

Answer 37

peptidyl transferase

Question 38

translocation of the peptide chain back to the P site is brought about by elongation factor _____

Answer 38

EF-G

Question 39

activated EF-TU is required for aminoacyl-tRNA to bind, and it is activated by ____

Answer 39

GTP

Question 40

____ is the second enzyme in addition to EF-TU that needs to be activated by GTP

Answer 40

EF-G

Question 41

the biding of release factors to the A site transforms the ribosomal peptydyl transferase into a ____, which breaks covalent bonds

Answer 41

hydrolase

Question 42

the presence of a ___ ____ at the A site brings about the binding of 2 release factors to the A site (always at lease RF-3) along with GTP

Answer 42

stop codon

Question 43

after dissocitation, there is ___ ____ between the pool of 50S ribosomes and 30S ribosomes

Answer 43

dynamic equillibrium

Question 44

a ____ is multiple ribosomes synthesizing proteins on a single mRNA molecule

Answer 44

polysome

Question 45

prokaryotic mRNAs can have up to _____ ribosomes attached

Answer 45

10

Question 46

what are Hsp70, GroES/GroEL exmaples of?

Answer 46

molecular chaperones that aide in the folding of proteins into the cell

Question 47

_____ percent of proteins require GroES/GroEL to fold (all else requires either none or Hsp70)

Answer 47

15