mRNA translation

Question 1

translation

Answer 1

RNA to protein

Question 2

protein function

Answer 2

metabolism
organisation
structure
development

Question 3

condensation reaction

Answer 3

peptide bond requires a lot of energy forming polymers

Question 4

location of synthesis

Answer 4

cytoplasm in ribosomes

in 5’ to 3’ direction and in N to C direction

Question 5

ribosome contain

Answer 5

RNA and protein - complex enzymes

Question 6

function of ribosome

Answer 6

read mRNA and translate = amino acid sequence and assemble them to form polymer

Question 7

eukaryotic ribosomes

Answer 7

80s containing 60s and 40s

Question 8

60s

Answer 8

> 49 proteins and 3 rRNA

Question 9

40s

Answer 9

> 33 proteins and 1 rRNA

Question 10

prokaryotic ribosomes

Answer 10

70s containing 50s and 30s

Question 11

50s

Answer 11

34 proteins and 2 rRNA

Question 12

30s

Answer 12

21 proteins and 1 rRNA

Question 13

catalysis for ribosomes

Answer 13

rRNA components such as ribozymes

Question 14

tRNA

Answer 14

75 nucleotides long

adopt folded structure with internal base pairing

Question 15

Ribosome structure

Answer 15

E-site - exiting of mRNA
P-site - transcription occurs
A-site - mRNA enters

Question 16

small ribosomal subunit

Answer 16

has mRNA binding site

Question 17

inactive proteins

Answer 17

when one or two bases are added in RNA

Question 18

active protein

Answer 18

adding 3 bases in the RNA

Question 19

singlet code

Answer 19

only gives 4 possibilities

Question 20

doublet code

Answer 20

gives 16 (4(2)) combination

Question 21

triplet code

Answer 21

64 combination (4(3))

Question 22

quartet code

Answer 22

256 combination (4(4))

Question 23

cracking genetic code in in vitro translation

Answer 23

polyu - polyphenylalanine

Question 24

dinucleotide

Answer 24

alternating e.g. UAUAUAUA

either be UAU or AUA

Question 25

trinucleotide

Answer 25

AAGAAGAAG | could be AAG or AGA or GAA

Question 26

tetranucleotide

Answer 26

UAUCUAUCUAUCUAUC | could be UAU, AUC, UCU, CUA

Question 27

experimenting on cracking genetic code | if have 76% U and 24% G

Answer 27

started at random 8 possibilities UUU, UUG, UGU, GUU, GUG, GGU, UGG, GGG likelihood of UUU is 0.76*0.76*0.76 = 44%

Question 28

code - triplet

Answer 28

degenerate, non-overlapping | and no punctuation

Question 29

code of life - table

Answer 29

universal with few exception

Question 30

translation in mitochondria

Answer 30

uses specific ribosomes and different sets of tRNA genes | similar system as chloroplast

Question 31

protein synthesis - initiation in bacteria

Answer 31

ribosome binding site | has shine-Dalgarno sequence complementary 3' end of 16s rRNA

Question 32

protein synthesis - initiation in eukaryotes

Answer 32

starts AUG from 5' has good context ; gcc (A/G)ccAUGG

Question 33

adaptor molecule

Answer 33

amino acids linked to tRNA

Question 34

first amino acid

Answer 34

methionine AUG

Question 35

anticodon

Answer 35

complementary to codon triplet on mRNA

Question 36

charging of tRNA

Answer 36

activation of amino acids | formation of aminoacyl-tRNA

Question 37

activation of amino acid

Answer 37

ATP + amino acid -> amoniacyl adenylate +PPi

Question 38

formation of aminoacyl-tRNA

Answer 38

aminoacyl adenylate + tRNA -> aminoacyl-tRNA + AMP

Question 39

aminoacyl-tRNA synthases

Answer 39

ensure fidelity of addition

Question 40

addition of further amino acid - elongation

Answer 40

translocation peptidyl-transferase activity transfers next amino acid onto growing peptide by condensation reaction

Question 41

translocation

Answer 41

movement of triplets to triplets

Question 42

peptidyl-transferase activity

Answer 42

transferring of the next amino acid

Question 43

mRNA decorating

Answer 43

with many ribosomes (polysomes) | move along message at different points of protein synthesis

Question 44

transcription and translation in bacteria

Answer 44

coupled - occur at the same time

Question 45

transcription and translation in eukaryotes

Answer 45

compartmentalised and then mRNA exported to cytoplasm

Question 46

termination of protein synthesis

Answer 46

stop codons | completes polypeptide chain - released

Question 47

ribosomal subunit after termination

Answer 47

dissociate and go on new round of initiation

Question 48

stop codons

Answer 48

UAA, UAG, UGA

Question 49

mutation missense

Answer 49

change of one base but able to get away with it

Question 50

nonsense

Answer 50

change in base to a stop codon - producing shorter protein

Question 51

silent mutation

Answer 51

change in base but no change in amino acid

Question 52

frameshift base deletion

Answer 52

base deleted - affecting the rest of the chain

Question 53

disrupting - streptomycin

Answer 53

freeze initiation complex and cause misreading of mRNA

Question 54

tetracycline

Answer 54

prevent binding of incoming aminoacyl-tRNA

Question 55

chloramphenicol

Answer 55

inhibits peptidyl transferase

Question 56

erytromucin

Answer 56

binds to 50s and inhibits translocation

Question 57

puromycin

Answer 57

mimics terminals of aminoacyl-tRNA | added onto growing chain causing premature termination

Question 58

one disrupting protein synthesis effect our cells as well

Answer 58

puromycin