Inhibitors of protein synthesis 1

Question 1

Who discovered the 30S bacterial subunit?

Answer 1

Ramakrishnan

Question 2

How much of the dry weight of bacterial cells are due to ribosomes?

Answer 2

30%

Question 3

What is a ribosome made up of?

Answer 3

55 proteins and 3 RNA strands

Question 4

How much energy does protein synthesis take up in a bacterial cell?

Answer 4

40%

Question 5

What is tetracycline biosynthesised from?

Answer 5

acetate by species of streptomyces

Question 6

Which part are tetracyclines resistant to?

Answer 6

membranes mostly but mutations in S10 can lead to resistance

Question 7

Why is tetracycline contraindicated in children?

Answer 7

causes staining to growing tooth enamel

Question 8

What is chlortetracycline used for?

Answer 8

conjunctivitis in cats

Question 9

Which 2 tetracyclines are used to treat acne?

Answer 9

oxytetracycline and lymecycline (later for severe acne as it is 5000x more soluble)

Question 10

Which tetracycline is used to treat Foulbreed in honeybees and what is this disease caused by?

Answer 10

oxytetracycline - melicssococcus plutonius

Question 11

What is the overall structure of aminoglycoside antibiotics?

Answer 11

sugar rings and one or more amino acid group

Question 12

How does streptomycin work and how is it administered?

Answer 12

binds 30S - specifically to 16S RNA causing misfunctioning of the ribosome where the genetic code is misread
IM injection

Question 13

Why is gentamicin spelt micin not mycin?

Answer 13

because it isn’t synthesised from streptomyces but from micromonospora instead

Question 14

How does tobramycin work?

Answer 14

binds to 30S and 50S ribosomal subunits preventing them combining

Question 15

What is amikacin derived from?

Answer 15

kanamycin

Question 16

How does linezolid work?

Answer 16

binds to 50S subunit and prevents 30S from joining it, however it is toxic to mitochondria ribosomes as they have 70S.