BIOL 3150 - FINAL EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED
Organism may be able to pump out the drug or stop it from being transported into
the cell. e.g., Efflux pumps or changes to porins.
1 type of major mechanism of antibiotic resistance:
Organism may be able to use alternate pathways (e.g., for obtaining folic acid)
1 type of major mechanism of antibiotic resistance: Eg. Folic acid synthesis.
•BActeria can make their own folic acid..
•Normally pteredine binds to PABA, sulfa drugs outcompete the PABA
•1)Bacteria could increase the conc of PABA so the antibiotic (sulfa drug) will be out
competed (u[ to 70x more than wat it would express)
•2)There could also be mutations in the enzyme dihydoteroat synthetase , the enzyme
still works but it is not effected by the drug anymore so now it can still produce the follic
acid but the ones that have the tereidne bound to the sulfa drug will not work but the
ones that are PABA an teredine will still produce folic acid? (mutate it to become more
specific)
•3) certain species have bypassed the use of this pthway, use a completley differen
pathway to synthesize their nucleic acids
•4)They eliminate the picking up of folic acid thorugh this, and instead it will upregulate
the genes in order to pick up the follic acid from the environment
Organism may be able to modify the drug to an inactive form.
, 1 type of major mechanism of antibiotic resistance: •Organism can break the b-lactam
ring and then it cant bind to transpeptidase
•Genes for these enzymes found on chromosomal DNA or plasmids (R-plasmids)
•They have identified 190 different b-lactamase enzymes in several different species.
Organism may be impermeable to the drug
1 type of major mechanism of antibiotic resistance: •This relates to the gram (-), it has a
LPS layer so certain antibiotics that target the cell wall, will have a hard time targetting
the cell wall of the gram (-) bacteria because of this big LPS layer
organism that lacks the structure the drug targets
1 type of major mechanism of antibiotic resistance
decreased influx
This type of antibiotic gene codes for: these are changes to porins (in gram negative
bacteria)
Antibiotic inactivation
This type of antibiotic gene codes for: Some bacteria thave enzymes that can -----------
antibiotcs eg of this is the beta lactomases
Increased efflux
This type of antibiotic gene codes for: when a bacteria overexpresses this mechanism
to pump the antibiotic out. This results in never reaching the MIC value in the bacterial
cell.
Target site alterations
This type of antibiotic gene codes for: Antibiotics that ________ specific ________ and
__________ it. Eg. they attack ribosomes, RNAp, DNA gyrase. However, it is possible
COMPLETE SOLUTIONS VERIFIED
Organism may be able to pump out the drug or stop it from being transported into
the cell. e.g., Efflux pumps or changes to porins.
1 type of major mechanism of antibiotic resistance:
Organism may be able to use alternate pathways (e.g., for obtaining folic acid)
1 type of major mechanism of antibiotic resistance: Eg. Folic acid synthesis.
•BActeria can make their own folic acid..
•Normally pteredine binds to PABA, sulfa drugs outcompete the PABA
•1)Bacteria could increase the conc of PABA so the antibiotic (sulfa drug) will be out
competed (u[ to 70x more than wat it would express)
•2)There could also be mutations in the enzyme dihydoteroat synthetase , the enzyme
still works but it is not effected by the drug anymore so now it can still produce the follic
acid but the ones that have the tereidne bound to the sulfa drug will not work but the
ones that are PABA an teredine will still produce folic acid? (mutate it to become more
specific)
•3) certain species have bypassed the use of this pthway, use a completley differen
pathway to synthesize their nucleic acids
•4)They eliminate the picking up of folic acid thorugh this, and instead it will upregulate
the genes in order to pick up the follic acid from the environment
Organism may be able to modify the drug to an inactive form.
, 1 type of major mechanism of antibiotic resistance: •Organism can break the b-lactam
ring and then it cant bind to transpeptidase
•Genes for these enzymes found on chromosomal DNA or plasmids (R-plasmids)
•They have identified 190 different b-lactamase enzymes in several different species.
Organism may be impermeable to the drug
1 type of major mechanism of antibiotic resistance: •This relates to the gram (-), it has a
LPS layer so certain antibiotics that target the cell wall, will have a hard time targetting
the cell wall of the gram (-) bacteria because of this big LPS layer
organism that lacks the structure the drug targets
1 type of major mechanism of antibiotic resistance
decreased influx
This type of antibiotic gene codes for: these are changes to porins (in gram negative
bacteria)
Antibiotic inactivation
This type of antibiotic gene codes for: Some bacteria thave enzymes that can -----------
antibiotcs eg of this is the beta lactomases
Increased efflux
This type of antibiotic gene codes for: when a bacteria overexpresses this mechanism
to pump the antibiotic out. This results in never reaching the MIC value in the bacterial
cell.
Target site alterations
This type of antibiotic gene codes for: Antibiotics that ________ specific ________ and
__________ it. Eg. they attack ribosomes, RNAp, DNA gyrase. However, it is possible
