Protein Synthesis - Translation

Question 1

What is Translation (Protein Synthesis)?

Answer 1

The process of turning instructions from mRNA into amino acid chains

Question 2

What are the triplets of bases known as in translation?

Answer 2

Codons

(read in the 5’ to 3’ direction)

Question 3

What are the termination (stop) codons?

Answer 3

1. UAA
2. UAG
3. UGA

Question 4

Which TWO amino acids have only single codons?

Answer 4

1. Methyanine - AUG
2. Tryptophan - UGG

Question 5

What structure do tRNA molecules have?

Answer 5

Cloverleaf

Question 6

Where does tRNA base pair with mRNA?

Answer 6

At the ANTICODON

1st base of mRNA codon to 3rd base of tRNA anticodon

Question 7

Where does the amino acid attach on a tRNA molecule?

Answer 7

3’ end

Question 8

What enzyme joins amino acids to tRNA?

Answer 8

Aminoacyl-tRNA Synthetase

Question 9

What does a synthetase do and how many different ones are there?

Answer 9

They join an amino acid to their tRNAs

There are 20

Question 10

What are the functions of rRNA?

Answer 10

1. Structural role - make up ribosomes
2. Catalytic role - catalyses the formation of peptide bonds

Question 11

What are the three binding sites for tRNA in a ribosome?

Answer 11

1. E-site
2. P-site
3. A-site

Question 12

What is the function of the P-site in a ribosome?

Answer 12

Holds the tRNA that carries the growing polypeptide chain

Question 13

What is the function of the A-site in a ribosome?

Answer 13

Holds the charged tRNA that carries the next amino acid to be added to the chain

Question 14

What is the function of the E-site in a ribosome?

Answer 14

The exit site, where discharged tRNAs leave the ribosome

Question 15

When does a tRNA molecule become charged?

Answer 15

When an amino acid is attached to it

Question 16

What subunits does a tRNA molecule contain?

Answer 16

30S (small) and 50S (large)

Question 17

What is an mRNA called when there are several ribosomes attached?

Answer 17

Polyribosome or Polysome