Proteins

Question 1

What enzymes bind amino acids to tRNA?

Answer 1

Aminoacyl-tRNA synthetases

Question 2

What 2 molecules are used as energy sources during translation?

Answer 2

ATP and GTP

Question 3

What is the first stage of tRNA to amino acid binding?

Answer 3

Aminoacyl-tRNA synthase for a specific enzyme binds to ATP and the amino acid

Question 4

What is the second stage of tRNA to amino acid binding?

Answer 4

ATP bound to the activating enzyme is hydrolysed to form AMP and a pyrophosphate

Question 5

What is the third stage of tRNA to amino acid binding?

Answer 5

The amino acid specific tRNA molecule binds to the enzyme

Question 6

What is the fourth stage of tRNA to amino acid binding?

Answer 6

The AMP is lost from the molecule leaving just the enzyme, tRNA and amino acid

Question 7

What is the fifth stage of tRNA to amino acid binding?

Answer 7

The tRNA and amino acid detach from the enzyme

Question 8

What size of ribosome is found in a prokaryote?

Answer 8

70S

Question 9

What size of ribosome is found in a eukaryote?

Answer 9

80S

Question 10

What are the 3 binding sites of ribosomes?

Answer 10

Exit
Peptidyl
Aminoacyl

Question 11

What is required for the initiation of translation?

Answer 11

Initiation factors
GTP
Methionine tRNA
40S subunit

Question 12

What is required to move the first methionine from the A binding site to the P binding site

Answer 12

ATP

Question 13

What allows for the binding of the large 60S subunit to the small 40S subunit?

Answer 13

The methionine initiator RNA

Question 14

What brings the second base of translation to the A site of the ribosomes?

Answer 14

An elongation factor (EF-1α)

Question 15

What enzyme catalyses the formation of peptide bone between amino acids?

Answer 15

Peptidyl transferase

Question 16

What moves the mRNA along the ribosome by 1 triplet?

Answer 16

EF-2

Question 17

What releases EF-1α from the aminoacyl-tRNA after it has been moved?

Answer 17

The hydrolysis of GTP

Question 18

What regenerates EF-1α to pick up the next aminoacyl-tRNA?

Answer 18

EFβγ

Question 19

What binds to stop codons to terminate translation?

Answer 19

A release factor

Question 20

What is a polysome?

Answer 20

A chain of ribosomes in which the same mRNA strand can move through to form many copies of the same protein

Question 21

Where do proteins formed by free ribosomes move to?

Answer 21

Cytosol
Nucleus
Mitochondria

Question 22

Where do proteins formed by bound ribosomes move to?

Answer 22

Plasma membrane
ER
Golgi apparatus
Secretion

Question 23

When are proteins from free ribosomes translocated?

Answer 23

Post-translationally (After translation)

Question 24

When are proteins from bound ribosomes translocated?

Answer 24

Co-translationally (During translation)

Question 25

What is I-cell disease/mucolipidosis II?

Answer 25

An inherited disease in which proteins normally destined for ribosomes are not sorted in the golgi, so they are secreted from the cell. This means lysosomes can't properly digest material

Question 26

What is glycosylation?

Answer 26

Addition and processing of carbohydrates in the ER and golgi