Translation

Question 1

Translation

Answer 1

Synthesis of a polypeptide specified by an mRNA

Question 2

Codon

Answer 2

A triplet of bases that code for 1 amino acid

Question 3

Starting point

Answer 3

Sets the reading frame

Question 4

Characteristics of the genetic code

Answer 4

Universal, non-overlapping, degenerate

Question 5

Degenerate

Answer 5

More than one codon can code for the same amino acid

Question 6

Nonsense mutation

Answer 6

Introduces a stop codon which produces an incomplete polypeptide

Question 7

Frameshift mutations

Answer 7

Deletes or inserts a base which changes the whole amino acid sequence

Question 8

Transition point mutation

Answer 8

Substituting a purine/pyrimidine for another purine/pyrimidine

Question 9

Transversion point mutation

Answer 9

Substituting a purine for a pyrimidine or vice versa

Question 10

Transfer RNA

Answer 10

Has a stem-loop structure, it is made up of an acceptor stem, D loop, anticodon loop, variable loop and Tc loop

Question 11

Acceptor stem

Answer 11

Site of aminoacylation

Question 12

D loop

Answer 12

Contains the modified base dihydrouridine which stabilizes the tRNA structure

Question 13

Anticodon loop

Answer 13

Recognizes codon on mRNA

Question 14

Variable loop

Answer 14

It varies in size and structure, and its not always present

Question 15

T¥C loop

Answer 15

Recognition site for enzymes for protein synthesis

Question 16

Ribosome structure

Answer 16

Made up of r RNA and peptides, and consists of the A site, P site and E site

Question 17

A site

Answer 17

Binds incoming aminoacyl-tRNA

Question 18

P site

Answer 18

Binds peptidyl tRNA

Question 19

E site

Answer 19

Exit site for uncharged tRNA

Question 20

Sedimentation coefficient (s)

Answer 20

Measures particle’s size by sedimentation rate

Question 21

N-formylated Met

Answer 21

A formyl group added to a methionine , its tRNA initiates translation since it is the one that is recognized by the start codon

Question 22

Shine- dalgarno sequence

Answer 22

A purine rich tract in mRNA that helps recruit the ribosome to the start codon, only found in prokaryotes

Question 23

Initiation factors

Answer 23

Proteins that bind to the small ribosomal unit

Question 24

Initiation

Answer 24

Inactive ribosomes are dissociated
mRNA, fMet-tRNA, GTP, IFs bind to 30S
GTP releases a phosphate
50S and 30S join, fMet-tRNA enters P site and A site is ready to accept AA-tRNA

Question 25

Elongation

Answer 25

Uses elongation factors and is done in the steps, AA-tRNA binding, transpeptidation, translocation, and termination

Question 26

AA-tRNA binding

Answer 26

It binds to the A site and GTP becomes GDP

Question 27

Transpeptidation

Answer 27

Formation of a peptide bond by peptidyl transferase so that the peptidyl can be transferred to the AA-tRNA

Question 28

Translocation

Answer 28

Previous peptidyl-tRNA moves to E site to get released and the new one moves to the P site

Question 29

Termination

Answer 29

Release factors recognize stop codons, this causes peptidyl transferase to transfer the peptidyl group to water. Release of phosphate by GTP causes the release of the RFs and inactivates the ribosomes

Question 30

Chloramphenicol

Answer 30

Inhibits peptidyl transferase on prokaryotic large subunit

Question 31

Cycloheximide

Answer 31

Inhibits peptidyl transferase on eukaryotic large subunit

Question 32

Erythromycin

Answer 32

Inhibits prokaryotic translocation

Question 33

Tetracycline

Answer 33

Inhibits binding of AA-tRNA to prokaryotic small subunit

Question 34

Diphtheria toxin

Answer 34

Catalytically inactivates eEF-2