Term
Penicillin was considered a miriacle drug for all of the following reasons except:
A It was the first antibiotic
B it doesn't affect eukaryotic cells
C It inhibits gram-positive cell wall synthesis
D it has selective toxicity
E it kills a bacteria |
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Definition
A. It was the first antibiotic |
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Term
A drug that inhibits mitosis, such as griseofulvin, would be more effective against:
A gram positive bacteria
B Gram negative bacteria
C fungi
D wall-less bacteris
E. Mycobacteria |
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Definition
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Term
Most of the available antimicrobial agents are effective against:
A viruses
B bacteria
C fungi
D protozoa
E All of the above |
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Definition
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Term
Antimicrobial peptides work by:
A inhibiting protein synthesis
B disrupting the plasma membrane
C complementary base pairing with DNA
D inhibiting cell-wall synthesis
E hydrolyzing peptidoglycan |
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Definition
B Disrupting the plasma membrane |
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Term
In what ways are semisynthetic penicillins and natural penicillins alike?
A both are broad spectrum
B both are resistant to penicillinase
C both are resistant to stomach acids
D both are bactericidal
D both are based on B-lactam |
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Definition
E. Both are based on B-lactam |
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Term
Which of the following antibiotics is not bactericidal?
A aminoglycosides
B cephalosporins
C polyenes
D rifampins
E penicillin |
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Definition
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Term
Which of the following does not belong with the others?
A bacitracin
B cephalosporin
C monobactam
D Penicillin
E streptomcin |
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Definition
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Term
The antibiotic tetracycline binds to the 30s subunit of the ribosome as shown in figure 20.1. The effect is to:
A prevent attachment of tRNA
B prevent peptide bond formation
C prevent transcription
D stop teh ribosome from moving along the mRNA
E. prevent attachment of tRNA and mRNA |
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Definition
B. prevent peptide bond formation |
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Term
The antibiotic cycloheximide binds to the 60s subunit of the ribosome as shown in figure 20.2 the effect is to:
A prevent mRNA -ribosome binding in eukaryotes
B prevent peptide bond formation in prokaryotes
C prevent poypeptide elongation in eukaryotes
D prevent transcription in prokaryotes
E prevent ribosome formation in bacteria
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Definition
C. Prevent polypeptide elongation in eukaryotes. |
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Term
Which of these antimicrobial agents has the fewest side effects:
A streptomycin
B tetracycline
c penicillin
D erythromycin
E chloramphenicol |
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Definition
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Term
Which of the following drugs does not act by competitive inhibition?
A ethambutol
B isoniazid
C streptomycin
D sulfonimide
E tetracycline |
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Definition
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Term
Which of the following methods of action would be bacteriostatic?
A competitive inhibition with folic acid synthesis
B inhibition of RNA synthesis
C injury to plasma membrane
D inhibition of cell wall synthesis
E competitive inhibition with DNA gyrase |
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Definition
B. Inhibition of RNA synthesis |
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Term
Which of the following antibiotics is recommended for use against gram-negative bacteria?
A polyenes
B bacitracin
C cephalosporin
D penicillin
E polymyxin |
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Definition
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Term
Which of the following antimicrobial agents is recommended for use against fungal infections?
A amphotericin B
B bacitracin
C Cephalosporin
D penicillin
E polymyxin |
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Definition
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Term
More than half of our antibiotics are
A produced by fungi
B produced by bacteria
C synthesized in laboratories
D produced by Fleming
E Produced by eukaryotic organisms |
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Definition
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Term
Which compound would be the most useful to treat candidiasis?
A uracil
B thymin
C flucytosine
D guanine
E Penicillin |
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Definition
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Term
Which of the following antibiotics are used to treat fungal infections
1 aminoglycosides
2cephalosporins
3 griseofulvin
4 polyenes
5 bacitracin
A 1,2,3
B 3, 4
C 3,4,5,
D 4,5
E all of the antibiotics
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Definition
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Term
Which of the following antibiotics does not interfere with cell wall synthesis?
A cephalosporins
B macrolides
C natural penicillins
d senisyntheti penicillins
E vancomycin |
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Definition
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Term
The antimicrobial drugs with the broadest spectrum of activity are:
A aminoglycosides
B chloramphenicol
C lincomycin
D macrolides
E tetracyclines |
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Definition
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Term
Which of the following statements is false?
A fluoroquinolone inhibits DNA synthesis
B acyclovir inhibits DNA synthesis
C amantadine inhibits release of viral nucleic acid
D Interferon inhibits glycolysis
E azoles inhibit plasma membrane synthesis
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Definition
D. Interferon inhibits interferon |
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Term
Protozoan and helminthic diseases are difficult to treat because:
A their cells are structurally and functionally similar to human cells
B They replicate insie human cells
C They dont have ribosomes
D They don't reproduce
E They have more genes than bacteria |
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Definition
A. Their cells are structurally and functionally similar to human cells |
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Term
Which of the following organisms would most likely be sensitive to natural penicillin?
A L forms
B streptococcus pyogenes
C penicillinase-producing Neisseria gonorrhoeae
D penicillium
E mycoplasma |
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Definition
B. Streptococcus pyogenes |
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Term
Which of the following statements about drug resistance is false?
A it may be carried on a plasmid
B it may be transferred from one bacterium to another during conjugation
C it may be due to enzymes that degrade some antibiotics
D it is found only in gram-negative bacteria
E it may be due to increased uptake of a drug |
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Definition
D. It is found only in gram-negative bacteria. |
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Term
Which of the following does not constitute an advantage of using two antibiotics together?
A it can prevent drug resistance
B It lessens the toxicity of individual drugs
C two are always twice as effective as one
D it allows treatment to be provided prior to diagnosis
E all of the above are advantages |
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Definition
C. Two are always twice as effective as one |
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Term
The structure of the influenza drug Tamiflu and Salic acid, the substrate for influenza virus's neuramidase, are shown in figure 20.6. What is the method of action of Tamiflu?
A inhibits cell wall synthesis
B inhibits plasma membrane synthesis
C inhibits synthesis of neuramidase
D competitive inhibition
E prevents synthesis of virus spikes |
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Definition
D. Competitive inhibition |
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Term
The antibiotic chloramphenicol Binds to the 50s subunit of the ribosome as shown in figure 20.3. The effect is to
A prevent attachment of tRNA
B prevent peptide bond formation
C prevent transcrition
D stop ribosome from moving along the mRNA
E prevent polypeptide formation in eukaryotes. |
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Definition
A. Prevent attachment of tRNA |
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Term
Drug resistance occurs
A because bacteria are normal microbiota
B when antibiotics are used indiscriminately
C against antibiotics and not against synthetic chemotherapeutic agents
D when antibiotics are taken after symptons disappear
E all of the above
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Definition
B. when antibiotics are used indiscriminately |
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Term
Which of the following would be selective against the tubercle bacillus?
A bacitracin - inhibits peptidoglycan synthesis
B ethambutol-inhibits mycolic acid synthesis
C streptogramin inhibits protein synthesis
D Streptomycin inhibits protein synthesis
D Vancomycin inhibits peptidoglycan synthesis |
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Definition
B. ethambutol- inhibits mycolic acid synthesis |
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Term
In the presence of penicillin, a cell dies because
A it lacks a cell wall
B it plasmolyzes
C it undergoes osmotic lysis
D it lacks a cell membrane
E its contents leak out |
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Definition
C. It undergoes osmotic lysis |
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Term
Lamisil is an allylamine used to treat dermatonycoses. Lamisil's method of action is similar to that of
A polymyxin B
B azole antibiotics
C echinocandins
D griseofulvin
E bactracin |
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Definition
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Term
Niclosamide prevents ATP generation in mitochondria. You would expect this drug to be effective against
A gram-negative bacteria
B gram-positive bacteria
C helminths
D mycobacterium tuberculosis
E viruses |
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Definition
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Term
Which of the following statements about drugs that competitively inhibit DNA polymerase or RNA polymerase is false?
A they cause mutations
B they are used against viral infections
C they can affect hot cell DNA
D they are too dangerous to use
E they interfere with protein synthesis |
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Definition
D They are too dangerous to use. |
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Term
Which of the following does not affect eukaryotic cells?
A antiprotozoan drugs
B antihelminthic drugs
C antifungal drugs
D nucleotide analogs
E semisynthetic penicillins |
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Definition
E. semisynthetic penicillins |
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Term
Mebendazole is used to treat cestode infections. It interfers with microtubule formation; therefore, it would not affect
A bacteria
B fungi
C helminths
D human cells
E protozoa
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Definition
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Term
Which of the following antibiotics causes misreading of mRNA
A aminoglycoside-changes shape of 30s units
B chloramphenicol-inhibits peptide bonds at 50s subunit
C oxazolidinine-prevents formation of 70s ribosome
D streptogamin - prevents release of peptide from 70s ribosome
E tetracyclines - bind with 30s subunit |
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Definition
A. aminoglycoside changes shape of 30s units |
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Term
The antibiotic actinomycin D binds between adjacent G-C pairs, thus interfering with
A transcription
B translation
C cellular respiration
D plasma membrane function
E peptide bond formation
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Definition
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Term
Use of antibiotics in animal feed leads to antibiotic-resistance bacteria because
A bacteria from other animals replace those killed by the antibiotics
B the few surviving bacteria that are affected by the antibiotics develop immunity to the antibiotics, which they pass on to their progeny
C the antibiotics cause new mutations to occur in the surviving bacteria which results in reistance
D the antibiotics kill susceptible bacteria but the few that are naturally resistant live and reproduce and their progeny repopulate the host
E the antibiotics persist in soil and water |
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Definition
D the antibiotics kill susceptible bacteria, but the few that are naturally resistant live and reproduce, and their progeny repopulate the host animal. |
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