Translation

Question 1

3 stop codons

Answer 1

UAA, UAG, UGA

Question 2

start codon

Answer 2

AUG

Question 3

wobble

Answer 3

1st position of anticodon, 3rd position of codon: can be several different bases and still lead to the same amino acid.
The same tRNA can recognize more than one codon.

Question 4

prokaryotic ribosome

Answer 4

70s
(50s subunit: composed of 5s and 23s) - 31 proteins
(30s subunit: composed of 16s) - 21 proteins

Question 5

eukaryotic ribosome

Answer 5

80s
(60s subunit: 5, 5.8, 28s) - 50 proteins
(40s subunit: 18s) - 33 proteins

Question 6

Ribosome synthesis occurs on _______, by polymerases __ and __.

Answer 6

nucleoli, pol I and III

Question 7

snoRNAs

Answer 7

guide chemical modifications of other RNAs

Question 8

how are rRNAs post transcriptionally modified?

Answer 8

High % methylation of ribose and conversion U -> psuedo U

Question 9

Shine-Dalgarno sequence

Answer 9

a ribosomal binding site in bacterial mRNA, generally located around 5-10 bases upstream (5’) of the start codon AUG. The RNA sequence helps recruit the ribosome to the mRNA to initiate protein synthesis by aligning the ribosome with the start codon.

Question 10

Diptheria toxin

Answer 10

Inactivates eEF2

Question 11

Chloramphenicol

Answer 11

Antibiotic that blocks peptidyl chain elongation on bacterial ribosomes, not eukaryotic ribosomes.
Distinguish mt photosynthesis from cytoplasmic photosynthesis.

Question 12

Tetracycline

Answer 12

Antibiotic that blocks binding of amino acyl tRNAs to the A-site (impermeable to eukaryotic plasma membrane)

Question 13

Streptomycin

Answer 13

antibiotic that interferes with pairing of aa tRNA and the codon

Question 14

Erythromycin

Answer 14

antibiotic that binds to the largest subunit RNA and interferes with translocation

Question 15

Puromycin

Answer 15

Antibiotic; premature chain termination

Question 16

Cycloheximide

Answer 16

Antibiotic selective for peptidyl transferase in eukaryotic ribosomes