L4 Translation

Question 1

how many amino acids are there?

Answer 1

20

Question 2

how many bases are in a codon

Answer 2

3

Question 3

Is the genetic code redundant or ambiguity

Answer 3

it is redundant- more than one codon can code for 1 amino acid but there is no ambiguity for what a codon codes for

Question 4

What is the start codon and which Amino acid does the tRNa carry

Answer 4

AUG- methionine

Question 5

what is a Silent mutation?

Answer 5

as there are more than one codon for an amino acid, a base can change and the codon still codes for the same amino acid

Question 6

Missense Mutuation?

Answer 6

one base changes and now the codon codes for a different AA- disfuncstional protein

Question 7

non-sense mutation?

Answer 7

now codes for a stop codon- rest of protein will be lost

Question 8

frameshift

Answer 8

addition or deletion of AA, as the code is read in 3s, all codons after the point will be misaligned-

Question 9

where are membrane proteins translated?

Answer 9

translated in the RER

Question 10

describe ribosomal subunits

Answer 10

2 subunits- small 40S, large 60S make Toal 80S eukaryotic ribosome

Question 11

what is the A site in a ribosome

Answer 11

Amino acid, where the tRNa comes in with the amino acid

Question 12

what is the p site?

Answer 12

polypeptide- tRNA adds amino cid to the growing chain

Question 13

what is the E site?

Answer 13

where the empty tRNA leaves the ribosome

Question 14

where does the Amino acid attacg to tRNA?

Answer 14

the 3’ short single stranded end

Question 15

which ribosomal subunit binds to mRNA?

Answer 15

small

Question 16

what type of tRNa recognises the AUG start codon

Answer 16

initiator tRNA carrrying Met- this is the only amino acid that begins in the P site

Question 17

what part of mRNA binds to the ribosome?

Answer 17

5’UTR, ribosome then scans the mRNA until it finds the start codon- initiation

Question 18

describe Termination of translation

Answer 18

at the stop codon- this does not code for an AA , is instead recognised by a release factor in the A site. the poly petite is released,

Question 19

3 stages of translation?

Answer 19

initiation
elongation
termination

Question 20

what type of bond joins 2 amino acids together

Answer 20

peptide bond in a condensation reaction between the Amino group of one AA and the carboxyl group of another produce a molecule of water

Question 21

what happens to a protein after termination?

Answer 21

undegoes further modification to produce functional protein- folding, adding sugars, phosphates etc