MICROBIOLOGY BIOD 171 MODULE 2 EXAM
2026 FINAL PAPER
◉ In inhibiting cell wall synthesis (action of antimicrobial drugs),
what does penicillin prevent the synthesis of? Answer:
peptidoglycan
◉ What Mode of Action of Antimicrobial Drugs?
-target bacterial 70S ribosomes
-chloramphenicol, erythromycin, streptomycin, tetracyclines
Answer: inhibiting protein synthesis
◉ What Mode of Action of Antimicrobial Drugs?
-polypeptide antibiotics change membrane permeability
-antifungal drugs combine with membrane sterols
-ionophores antibiotics allow uncontrolled movement of cations
(not for human use) Answer: injuring the plasma membrane
◉ What changes membrane permeability? Answer: polypeptide
antibiotics
,◉ combine with membrane sterols Answer: antifungal drugs
◉ allow uncontrolled movement of cations (not for human use)
Answer: ionophores antibiotics
◉ What mode of action of antimicrobial drugs?
-interfere with DNA replication and transcription Answer: inhibiting
nucleic acid synthesis
◉ What mode of action of antimicrobial drugs?
-antimetabolites compete with normal substrates for an enzyme
(Sulfanilamide competes with para-aminobenzoic acid *PABA*,
stopping the synthesis of folic acid) Answer: inhibiting the synthesis
of essential metabolites
◉ Sulfanilamide competes with ---------------, stopping the synthesis
of folic acid Answer: para-aminobenzoic acid (PABA)
◉ risk versus benefit Answer: therapeutic index
,◉ -therapeutic index: risk versus benefit
-reactions of antibiotics with other drugs
- damage to organs
-risk to the fetus Answer: antibiotic safety
◉ Misuse of antibiotics selected for resistance mutants. Answer:
antibiotic misuse
◉ Antibiotic misuse includes Answer: Using outdated or weakened
antibiotics
Using antibiotics for the common cold and other inappropriate
conditions
Using antibiotics in animal feed
Failing to complete the prescribed regimen
Using someone else's leftover prescription
◉ -enzymatic destruction or inactivation of the drug
-prevention of penetration to the target site within the microbe
-alteration of the drug's target site
-rapid efflux (ejection) of the antibiotic
-variations of mechanisms of resistance
, ALL OF THESE ARE EXAMPLES OF WHAT? Answer: mechanisms of
resistance
◉ microbes with genetic characteristics allowing for their survival
when exposed to an antibiotic Answer: persister cells
◉ bacteria that are resistant to large numbers of antibiotics Answer:
superbugs
◉ Resistance genes are often spread ---- among bacteria on ---- or
transposons via conjugation or transduction? Answer: horizontally
plasmids
◉ List 4 antiprotozoan drugs Answer: Quinine and chloroquine
artemisinin
metronidazole
miltefosine
◉ Treat malaria Answer: Quinine and chloroquine
◉ kills plasmodium that causes malaria Answer: artemisinin
◉ -also interferes with anaerobic bacteria
2026 FINAL PAPER
◉ In inhibiting cell wall synthesis (action of antimicrobial drugs),
what does penicillin prevent the synthesis of? Answer:
peptidoglycan
◉ What Mode of Action of Antimicrobial Drugs?
-target bacterial 70S ribosomes
-chloramphenicol, erythromycin, streptomycin, tetracyclines
Answer: inhibiting protein synthesis
◉ What Mode of Action of Antimicrobial Drugs?
-polypeptide antibiotics change membrane permeability
-antifungal drugs combine with membrane sterols
-ionophores antibiotics allow uncontrolled movement of cations
(not for human use) Answer: injuring the plasma membrane
◉ What changes membrane permeability? Answer: polypeptide
antibiotics
,◉ combine with membrane sterols Answer: antifungal drugs
◉ allow uncontrolled movement of cations (not for human use)
Answer: ionophores antibiotics
◉ What mode of action of antimicrobial drugs?
-interfere with DNA replication and transcription Answer: inhibiting
nucleic acid synthesis
◉ What mode of action of antimicrobial drugs?
-antimetabolites compete with normal substrates for an enzyme
(Sulfanilamide competes with para-aminobenzoic acid *PABA*,
stopping the synthesis of folic acid) Answer: inhibiting the synthesis
of essential metabolites
◉ Sulfanilamide competes with ---------------, stopping the synthesis
of folic acid Answer: para-aminobenzoic acid (PABA)
◉ risk versus benefit Answer: therapeutic index
,◉ -therapeutic index: risk versus benefit
-reactions of antibiotics with other drugs
- damage to organs
-risk to the fetus Answer: antibiotic safety
◉ Misuse of antibiotics selected for resistance mutants. Answer:
antibiotic misuse
◉ Antibiotic misuse includes Answer: Using outdated or weakened
antibiotics
Using antibiotics for the common cold and other inappropriate
conditions
Using antibiotics in animal feed
Failing to complete the prescribed regimen
Using someone else's leftover prescription
◉ -enzymatic destruction or inactivation of the drug
-prevention of penetration to the target site within the microbe
-alteration of the drug's target site
-rapid efflux (ejection) of the antibiotic
-variations of mechanisms of resistance
, ALL OF THESE ARE EXAMPLES OF WHAT? Answer: mechanisms of
resistance
◉ microbes with genetic characteristics allowing for their survival
when exposed to an antibiotic Answer: persister cells
◉ bacteria that are resistant to large numbers of antibiotics Answer:
superbugs
◉ Resistance genes are often spread ---- among bacteria on ---- or
transposons via conjugation or transduction? Answer: horizontally
plasmids
◉ List 4 antiprotozoan drugs Answer: Quinine and chloroquine
artemisinin
metronidazole
miltefosine
◉ Treat malaria Answer: Quinine and chloroquine
◉ kills plasmodium that causes malaria Answer: artemisinin
◉ -also interferes with anaerobic bacteria
