micro chapter 20 mode of action

Question 1

What are the five modes of action?

Answer 1

1. Inhibition of cell wall
2. Inhibition of protein synthesis
3. Inhibition of nucleic acid replication
4. injury to the plasma membrane
5. Inhibition of enzymatic activity

Question 2

Inhibition of cell wall synthesis
two ways?

Answer 2

1. Can prevent final cross-linking of teichoic acids
   2.Can interfere with the synthesis of linear peptidoglycan strands

Question 3

Inhibition of cell wall synthesis
prevent cross-linking examples

Answer 3

1. Penicillin
2. Methicillin
3. Cephalosporins

Question 4

inhibition of cell wall synthesis
Interfere with peptidoglycan examples

Answer 4

1. Vancomycin
2. Bacitracin

Question 5

inhibition of protein synthesis ways

Answer 5

affects the ribosomes

Question 6

Inhibition of protein synthesis
Bacteriostatic examples

Answer 6

1. Chloramphenicol
2. Tetracyclines
3. Erythromycin
4. Z- packs

Question 7

Inhibition of protein synthesis bactericidal example

Answer 7

1. Streptomycin

Question 8

inhibition of protein synthesis
50s subunit
Chloramphenicol and how it works

Answer 8

Chloramphenicol Inhibits peptide bond formation

Question 9

inhibition of protein synthesis
50s subunit
Erythromycin

Answer 9

Erythromycin reacts with 50s and prevents movement along the mRNA (Doesn’t penetrate the Gram - Cell wall too large)

Question 10

inhibition of protein synthesis
50s subunit
Zithromax (Z-packs)

Answer 10

Z-packs hitch a ride on WBC
goes to the site of infection
concentrates at the site of infection
(bacterial lung infection)

Question 11

inhibition of protein synthesis
30s subunit
Tetracyclines

Answer 11

Tetracyclines interfere with the attachment of tRNA (Anticodon) to mRNA (Codon)
works against Rickettsia (Ticks)
Chlamydia (STD)

Question 12

inhibition of protein synthesis
30s subunit shape
Aminoglycosides

Answer 12

Aminoglycosides (cidal)
Gentamicin, streptomycin, and neomycin
warps the shape of the 30s and the mRNA (codon) is read incorrectly

Question 13

Injury to the Plasma membrane and how it works

Answer 13

alters permeability
loss of metabolites thru the membrane (Leaks to death)
Polymyxin B attaches to phospholipids and disrupts membrane integrity
good for Gram-

Question 14

Inhibition of nucleic acid replication Rifamycin and how it works

Answer 14

Harder to get selective toxicity between the pros and euk
Inhibits DNA-dependent RNA polymerases
Active against gram + and some Mycobacterium (TB)
penetrates tissues well (topically only)

Question 15

Inhibition of enzymatic activity
Sulfanilamide and how it works

Answer 15

ability to “look like” normal substrate and competitively inhibit
Sulfanilamide blocks PABA
microbes use PABA to synthesis folic acid
bacteriostatic