Genetic code/protein synthesis

Question 1

How many bases code for one amino acid?

Answer 1

3

Question 2

How many possible amino acids can the genetic code make?

Answer 2

64

Question 3

Aug codes for?

Answer 3

Methionine and it is a start codon

Question 4

What are the three stop codons?

Answer 4

UAA, UGA and UAG

Question 5

Ugg codes for what amino acid?

Answer 5

trp

Question 6

The first column is green which means they are?

Answer 6

hydrophobic

Question 7

The yellow amino acids have what quality?

Answer 7

they are polar, have H bonds

Question 8

the pink amino acids are?

Answer 8

charged

Question 9

What is the most common amino acid for e. coli?

Answer 9

leucine at CUG

Question 10

what is the most common amino acid for humans?

Answer 10

leucine for CUG

Question 11

how many of the 64 codons make amino acids?

Answer 11

61

Question 12

All living systems do not use the same genetic code and it is not universal.

Answer 12

FALSE IT IS UNIVERSAL

Question 13

mitocondrial genomes show some differences, for example ____ specifies TRp rather than stop

Answer 13

UGA

Question 14

Are prokaryotic or eukaryotic ribosomes bigger?

Answer 14

eukaryotic

Question 15

What is found in the gap between the 50S and the 30S of the ribosome in E. coli?

Answer 15

mRNA is found

Question 16

initiation in protein synthesis involves….?

Answer 16

binding of mRNA to the small and large ribosomal
subunits, and binding of an initiator tRNA

Question 17

Elongation in protein synthesis involves….?

Answer 17

the formation of all peptide bonds of the growing
polypeptide chain

Question 18

Elongation in protein synthesis involves….?

Answer 18

the formation of all peptide bonds of the growing
polypeptide chain

Question 19

Termination in protein synthesis occurs when….?

Answer 19

Occurs when a “stop” codon is reached along the mRNA, which leads to the release of the completed polypeptide.

Question 20

In protein synthesis, a new aminoacyl-tRNA binds to the _________ site and then the
growing polypeptide at the P (peptidyl) site is transferred to the A site with the formation
of a peptide bond.

Answer 20

A (acceptor)

Question 21

is this in eukaryotes or prokaryotes?
Small subunit (30S)
16S rRNA
21 proteins
60% RNA/ 40% protein

Answer 21

prokaryotes

Question 22

is this in eukaryotes or prokaryotes?
Large subunit (50S)
23S and 5S rRNAs
31 proteins
70% RNA

Answer 22

prokaryotes

Question 23

is this in eukaryotes or prokaryotes?

Small subunits (40S)
18S rRNA
33 proteins
50% RNA/ 50% protein

Answer 23

eukaryotic

Question 24

is this in eukaryotes or prokaryotes?
Large subunits (60S)
28S, 5.8S, and 5S rRNAs
49 proteins
65% RNA/ 35% protein

Answer 24

eukaryote

Question 25

Rat liver ribosomes (80S) have a mass that is _____ times that of E. coli ribosomes

Answer 25

1.7

Question 26

Protein synthesis has three phases: initiation, elongation, and termination.

Answer 26

true

Question 27

what is initiation in protein synthesis

Answer 27

Involves binding of mRNA to the small and large ribosomal subunits, and then binding of an initiator tRNA

Question 28

what is elongation in protein synthesis

Answer 28

Includes the formation of all peptide bonds of the growing polypeptide chain

Question 29

what does termination do in protein synthesis

Answer 29

Occurs when a "stop" codon is reached along the mRNA

Question 30

what 5 factors are needed for peptide chain initiation.

Answer 30

(a) mRNA (b) 30S and 50S ribosomal subunits (c) initiation factors (d) GTP (e) initiator tRNA (f-Met-tRNA)

Question 31

what is needed for elongation in protein synthesis

Answer 31

(a) mRNA/ribosome/peptidyl-tRNA complex (b) aminoacyl-tRNAs (c) elongation factors (d) GTP

Question 32

For peptide chain termination, the components include:

Answer 32

(a) release factors (b) GTP

Question 33

Initiation begins with the binding of _____ and the initiator _____ (f-Met-tRNA) to the 30S ribosomal subunit. Initiation factors IF-1, IF-3, IF-2, and GTP are also required

Answer 33

mRNA and tRNA

Question 34

The initiator tRNA binds to the _____ _____ on the 30S subunit, and the 50S subunit joins the 30S subunit.

Answer 34

P site

Question 35

The 70S initiation complex consists of the 30S and 50S ribosomal subunits, mRNA, and the initiator tRNA bound to the P site. The mRNA and the tRNA are in the ____ _________ the two subunits

Answer 35

gap between

Question 36

the _______ blocks it so no more amino acids can be added.

Answer 36

formyl group

Question 37

in elongation in protein synthesis: Binding of a new aminoacyl-tRNA to the A site is brought about by elongation factor EF-___.

Answer 37

Tu

Question 38

Elongation factor EF-__ recycles EF-Tu

Answer 38

Ts

Question 39

in elongation______ __________ is the step that forms the peptide bond between the new amino acid and the growing polypeptide chain

Answer 39

Peptidyl transfer

Question 40

in elongation: The peptidyl transferase activity is not due to a protein enzyme, but to an ______ ________ activity of the “peptidyl transferase center” of the 23S rRNA of the 50S subunit.

Answer 40

RNA enzyme

Question 41

RNA enzymes are known as _________

Answer 41

“ribozymes”

Question 42

in elongation: Translocation of the peptide chain back to the P site is brought about by elongation factor EF-_

Answer 42

G

Question 43

In termination: The binding of ______ _____ to the A site transforms the ribosomal peptidyl transferase, that forms the peptide bond between amino acids, into a ______

Answer 43

release factors and hydrolase

Question 44

in termination: The peptidyl transferase then hydrolyzes the bond linking the polypeptide to its ______ _______, thereby releasing the polypeptide

Answer 44

tRNA carrier

Question 45

in termination:The presence of a _________ ______ at the A site brings about the binding of release factor RF-1 or RF-2 plus RF-3

Answer 45

stop codon (UAA, UAG, or UGA)

Question 46

in termination: The binding of the release factors transforms the ribosomal ______ _______ into a hydrolase that breaks the bond between the polypeptide and its tRNA carrier

Answer 46

peptidyl transferase

Question 47

The polypeptide is released, and the ____ ribosome dissociates from the mRNA

Answer 47

70S

Question 48

The proper folding of newly synthesized _______in the cell may require molecular __________ such as Hsp70 and GroES/GroEL

Answer 48

polypeptides and chaperones