lecture 17,18

Question 1

what is the decoding machine for translation?

Answer 1

tRNA + Ribosome (Protein and RNA)

Question 2

what is the information used for translation?

Answer 2

mRNA

Question 3

what is the result of translation?

Answer 3

a peptide chain and/or a protein

Question 4

what are the building blocks of protein?

Answer 4

amino acids

Question 5

how many amino acids are there?

Answer 5

20

Question 6

what does it mean for an amino acid to be degenerate?

Answer 6

some amino acids have more than one codon assignment

Question 7

how many bases encode for 1 amino acid?

Answer 7

3

Question 8

DNA mutation

Answer 8

permanent change in the DNA sequence

Question 9

base substitution mutation

Answer 9

when a base pair is swapped for a different base pair

Question 10

insertion mutation

Answer 10

when a base pair is added into the DNA sequence

Question 11

deletion mutation

Answer 11

when a base pair is removed from the DNA sequence

Question 12

do insertion/deletion mutations have an upstream or downstream mutation?

Answer 12

downstream

Question 13

overlapping genetic codes

Answer 13

When a single base substitution alters multiple amino acids

Question 14

what connects the mRNA to the protein during translation?

Answer 14

tRNAs

Question 15

wobble

Answer 15

refers to the flexibility of the third position of a codon in mRNA and the first position of an anticodon in the tRNA

Question 16

what is the purpose of wobble?

Answer 16

helps optimize and simplify protein synthesis by reducing the minimal number of tRNAs required

Question 17

what are some pairings allowed by wobble rules?

Answer 17

G can pair to U, U can pair to G, and I can pair to U,C, and A

Question 18

what is inosine?

Answer 18

a rare based used in tRNA

Question 19

what is the ribosome unit for prokaryotes?

Answer 19

70S ribosome

Question 20

what is 70S ribosome broken into in prokaryotes?

Answer 20

50S and 30S ribosomal subunits

Question 21

what is the ribosome unit for eukaryotes?

Answer 21

80S ribosome

Question 22

what is 80S ribosome broken into in eukaryotes?

Answer 22

60S and 40S ribosomal subunits

Question 23

how often should a random mRNA sequence have a start codon?

Answer 23

Every 64 codons

Question 24

in prokaryotes, what helps the initiator codon start in the right place for translation?

Answer 24

Shine-Dalgarno sequence

Question 25

where can the Shine-Dalgarno sequence be found?

Answer 25

about 8-10 nucleotides upstream from the start site AUG

Question 26

how is the start codon inserted into the ribosome?

Answer 26

by a special tRNA called an initiator

Question 27

what is the initiator in translation?

Answer 27

tRNA (Meti)

Question 28

what do initiation factors do in prokaryotes?

Answer 28

it keeps the ribosome subunits apart and ensure that only a tRNA (fMet) is brought in

Question 29

what do initiation factors do in eukaryotes?

Answer 29

They associate with the 5' cap, 40S subunit, and initiator tRNA to form an initiation complex and remove secondary RNA structures

Question 30

EF-Tu

Answer 30

an elongation factor that brings Aminoacyl tRNA to the ribosome

Question 31

aminoactyl-tRNA?

Answer 31

the tRNA that carries the amino acid

Question 32

EF-G

Answer 32

an elongation factor that moves the ribosome to the next codon for translation

Question 33

what happens when the ribosome reaches the stop codon?

Answer 33

water molecules get into the peptide transfer center and releases the peptide, before disassembling itself

Question 34

what does Shine-Dalgarno sequence do?

Answer 34

It serves as a ribosome binding site that helps position the ribosome in the correct location for translation to start

Question 35

release factors

Answer 35

ribosome components that recognize stop codons at the A site

Question 36

what are the tRNA binding sites?

Answer 36

aminoacyl, peptidyl, exit