Lesson 7

Question 1

(E-test) Epsilometer test :-

Answer 1

action of a specific antimicrobial

Question 2

B-lactams :-

Answer 2

bactericide
Targets the penicillin banding proteins (PBPs) (the hormone that synthesis the plasma membrane)
Inhibits the Synthesis of the Plasma membrane of bacteria (by effecting the PBPs)
Resistant
1-PBPs become unaffected by B-lactmas
2-destroy B-lactams

Question 3

Glycopeptides :-

Answer 3

bactericide
Effect only germ + bacteria
Targets the NAG and NAM (D-Ala-D-Ala)
Inhibits the Synthesis of the Plasma membrane of bacteria (by bending to NAG - NAM)
Resistant
By changing (D-Ala-D-Ala) to (D-Ala-D-lac)

Question 4

Macrolides :-

Answer 4

Bacteriostatic
Targets Ribosome (50 subunit) 
Stops the Translation inhibition (band to tRNA)
Resistant
1-has a pump to pump the antibiotic out
2-changes the tRNA

Question 5

Aminoglycosides :-

Answer 5

Bacteriostatic
Effect only Germ + aerobic bacteria
Targets Ribosome (30 subunit)
Changes the structure of tRNA to make useless protein
Resistant
1-changes the structure of Aminoglycosides
2-changes the structure of tRNA
3-it is ineffective in anaerobic bacteria because Aminoglycosides can not enter through plasma membrane

Question 6

Tetracyclines :-

Answer 6

Bacteriostatic
Targets Ribosome (30 subunit)
Stops the Translation inhibition (band to tRNA)
Resistant
1-make a protein band to tRNA to change the structure of tRNA
2-make a protion bend to antibiotic so it can’t bend to tRNA
3-make more pumps to pump the antibiotic out

Question 7

Oxazolidinones

Answer 7

Bacteriostatic
Effect only Germ + bacteria 
Targets Ribosome (50 subunit) 
Changes the structure of tRNA to make useless protein
Resistant
changes in tRNA structure

Question 8

Streptogramins :-

Answer 8

Bacteriostatic
Targets Ribosome (50 subunit)
Change the structure of tRNA to make useless protein
Resistant
1-changes the structure of tRNA
2-changes the structure of streptogramins
3-makes more pumps to pump the streptogramins out

Question 8

Rifamycins :-

Answer 8

Bacteriostatic
Targets RNA polymerase
Transcription inhibition
Resistant
Changes RNA polymerase

Question 9

Fluoroquinolones :-

Answer 9

bactericide
Stops cell replication
Targets DNA gyrase or/and topoisomerase IV
Resistant
Changes the structure of enzymes

Question 10

What is Protothrophs and Auxotrophs?

Answer 10

Protothrophs :- bacteria can survive because there are enough material
Auxotrophs :- bacteria can not survive because there are no enough material

Question 11

Types of recombinations in bacteria?

Answer 11

transformation :- by plasmid or free dna in environment (must be in hard situations like heat, electric change, starving or cell density)
transduction :- by bacteriophages by transfer of a DNA form one bacteria to other (when a bacteria is killed sometimes some of DNA reminds in the bacteriophages and transfer form one to another (in lytic and ly sometimes cycles))
conjugation :- the plasmid transfer form one bacteria to other by cytoplasmic bridge