Chapter 10 Flashcards
Drugs def
chemicals that affect physiology in any manner
therapeutic agents def
drugs that act against diseasea
antimicrobials def
drugs that treat infections
alexander fleming did what
discovered penicillium
zone of inhibiiton def
zone around a substance that it empty and does not contain the surrounding bacteria
successfull mechanisms are what
selective toxicity
are antibacterial drugs many and diverse or scare and limited
many and diverse
selective toxicity def
target structures or processes in microbe thats distinct from host
why are there fewer drugs for eukaryotic infections
cuz fungi are eukaryotes and similar to humans. for bacteria its easy to just target the peptidoglycan layer
are antiviral drugs abundant or limited
limited
what are the 5 processes and structures that might be targetted in bacteria
cell wall, proteins, membranes, metabolic pathways, and DNA/RNA synthesis
what is the most common way to inhibit cell wall synthesis of bacteria
to target and inhibit peptidoglycan
how is peptidoglycan inhibited
by preventing the cross linkage of NAM subunits.
is NAM only in bacteria
yes
what are beta lactams
a peptidoglycan inhibitor that prevents replication by binding to enzymes that cross-link NAM subunits
ex of beta lactam
penicillin
What can osmotic pressure cause in a weak cell wall
lysis
what do antibiotics weaken
peptidoglycan, meaning no longer a rigid shape
vancomycin does what
interferes with NAM bridges in many G+ bacteria
what does vancomycin bind to
binds to D-alanine to prevent cross linkage
what does bacitracin do
blocks transport of NAG and NAM across the cellular membrane so they never reach the cell wall
What does inhibition or protein synthesis and translation target
prokaryotic 70 S ribosomes.
advoids eukaryotic ribosomes (80S)
what is a potential negative of inhibiting protein synthesis
that mitochondira of animsal and humans contain 70 S ribosomes which could be harmful
disruption of cytoplasmic membranes is accomplished how
by forming channels through the membrane and damaging its integrity
what does amphotericin B do
binds to ergosteral in fungal membranes
what does polymyxin do
disrupts G- bacterial membrane
How ara metabolic pathways inhibited
with antimetabolic agents
when are antimetabolic agents effective
when pathogen and host metabolic processes differ
What is a sulfonamide
a metabolism inhibitor
what do sulfonamides do
inhibit nucleotide production
what do para-aminobenzoic acid and sulfanilamide make
folic acid
what do competitive inhibitors with PABA do
prevent folic synthesis
do humans make folic acid
no
How are nucleic acid syntheses inhibited
with several drugs that block DNA replication or RNA transcription
what do drugs for nucleic acid synthesis affect
both Euk and Prok cells
are nucleic acid synthesis inhibitor druggs used to treat infections
no they are used for research and to inhibit cell replication
what do nucleotide or nucleoside analogs do
distort shapes of nucleic acids,
prevent replication, transcription, or translation,
when are nucleotide or nucleoside analogs most effective
they are mostly used against viruses and are most effective against rapidly dividing cells
spectrum of action def
number of diff pathogens a drug acts against
narrow spectrum def
effective against few organisms
broad spectrum
effective against many organisms
what are the two ways resistance by bacteria is acquired
by new mutation in genes
or by acquiring R plasmids via transformation, transduction, and conjugation
what is the first mechanism of drug resistance
modifying the target of the antibiotic
what is the second mechanism of drug resistance
degrade drug before entry
what is the third mechanism of drug resistance
altering drug once in side
what is the fourth mechanism of drug resistance
minimizing the concentration of antibiotic in the cell
what is the fifth mechanism of drug resistance
biofilm formation
what are the ways mutation is a mechanism of drug resistance
modifying the target of the antibioticw
what are the ways that R-plasmid is a mechanism of drug resistance
degrade drug outisde cell, alter drug inside cell, minimize drug conc in cell (pump out)
