Lecture 16- translation & post-translational modification

Question 1

The ribosome binds …. so that codons can be read and has binding sites for …. molecules

Answer 1

mRNA
tRNA

Question 2

The ribosome catalyses …. bond formation

Answer 2

peptide

Question 3

Prokaryotic ribosomes are ….S with small ….S and ….S subunits

Answer 3

70
30
50

Question 4

What are the 3 tRNA-binding sites on ribosomes?

Answer 4

A site, P site, E site

Question 5

Ribosome A site function

Answer 5

Accommodates the incoming aminoacyl-tRNA

Question 6

Ribosome P site function

Answer 6

Accommodates the tRNA attached to growing peptide chain

Question 7

Ribosome E site function

Answer 7

Accommodates the tRNA, without amino acid, that is leaving

Question 8

All tRNAs have …. bound to … subunit & the rest of the tRNA bound to …. subunit

Answer 8

Anticodons
30S
50S

Question 9

Eukaryotic ribosomes are ….S with small ….S and ….S subunits

Answer 9

80
40
60

Question 10

Polycistronic

Answer 10

1 or less coding regions

Question 11

Monocystronic

Answer 11

1 coding region

Question 12

Initiation phase of translation:
-Ribosome recognises the …….
-Initiating codon is recognised by special ….

Answer 12

Start codon (AUG)
tRNA

Question 13

Elongation phase of translation:
Involves addition of …. to the … end of the growing chain

Answer 13

Amino acids
Carboxyl

Question 14

Elongation phase of translation:
- the b=ribosome advances ….. to mRNA 3’ end known as …..

Answer 14

3 nucleotides
transolcation

Question 15

Termination phase of translation:
-Termination codon encountered at ….
-….. binding causes …. of bond linking peptide to tRNA in ….

Answer 15

-A site
-RF (release factor)
hydrolysis
P site

Question 16

The majority of antibiotics block….

Answer 16

translation

Question 17

Once proteins have been produces they can be heavily modified. This affects … and …

Answer 17

Protein localisation
activity

Question 18

Phosphorylation occurs on …., is catalysed by …. and is reversed by ….

Answer 18

hydroxyl groups, kinases and reversed by phosphatases

Question 19

Many proteins that are secreted have a ….. attached

Answer 19

carbohydrate chain