bio145 quiz 6 (ch 10) Flashcards
An antimicrobial that inhibits cell wall synthesis will result in which of the following?
A) The replication of cells, including cancer cells, slows down.
B) Cells become more susceptible to osmotic pressure.
C) Cells cannot attach to their hosts.
D) Ribosomes lose their function.
E) The sterols in the cell wall become nonfunctional.
B) Cells become more susceptible to osmotic pressure.
Beta-lactam antibiotics have an effect on which of the following types of cells? A) virus-infected cells B) animal cells C) fungal cells D) bacterial cells E) both animal and fungal cells
D) bacterial cells
Which of the following is NOT a target of drugs that inhibit protein synthesis?
A) movement of the ribosome from one codon to the next
B) interference with alanine-alanine bridges
C) the enzymatic site of the 50S ribosomal subunit
D) the shape of the 30S ribosomal subunit
E) the tRNA docking site
B) interference with alanine-alanine bridges
Which scientist coined the term antibiotic? A) Waksman B) Fleming C) Domagk D) Ehrlich E) Kirby
A) Waksman
The most limited group of antimicrobial agents is the \_\_\_\_\_\_\_\_ drugs. A) anthelmintic B) antibacterial C) antiviral D) antiprotozoan E) antifungal
C) antiviral
Which of the following groups of drugs can become incorporated into fetal bones and teeth? A) beta-lactams B) aminoglycosides C) tetracyclines D) sulfonamides E) quinolones
C) tetracyclines
Which of the following statements concerning development of antibiotic resistance is FALSE?
A) It is often mediated by R-plasmids.
B) Resistant cells are normally in the minority in a bacterial population.
C) New resistance genes can be gained through transformation, transduction, or conjugation.
D) Resistance can occur through mutation of existing bacterial genes.
E) Resistant cells grow more efficiently and quickly than susceptible cells.
E) Resistant cells grow more efficiently and quickly than susceptible cells.
β-lactamase production is an example of which of the following types of resistance?
A) change in the permeability of the drug
B) removal of the drug via a pump
C) inactivation of the drug
D) overproduction of an enzyme in a key metabolic pathway
E) alteration of the target of the drug
C) inactivation of the drug
Most drugs that inhibit the synthesis of the cell wall act by
A) disrupting the formation of the mycolic acid layer of the cell wall.
B) preventing the formation of β-lactamases.
C) blocking the secretion of cell wall molecules from the cytoplasm.
D) preventing the formation of alanine-alanine bridges.
E) preventing the cross-linkage of NAM subunits.
E) preventing the cross-linkage of NAM subunits.
Most broad-spectrum antibiotics act by: A) disrupting the cytoplasmic membrane. B) inhibiting nucleic acid synthesis. C) inhibiting the synthesis of the cell wall. D) inhibiting metabolic pathways. E) inhibiting protein synthesis.
E) inhibiting protein synthesis.
Sulfonamides
A) were the first widely used antimetabolic antimicrobial and indirectly inhibit nucleic acid synthesis.
B) indirectly inhibit the synthesis of nucleic acids.
C) are no longer widely used.
D) are antimetabolic drugs.
E) were the first widely used antimicrobial drugs.
A) were the first widely used antimetabolic antimicrobial and indirectly inhibit nucleic acid synthesis.
Which of the following pathways is specifically inhibited by sulfonamides?
A) the conversion of PABA to dihydrofolic acid
B) the conversion of tetrahydrofolic acid to PABA
C) the conversion of dihydrofolic acid to PABA
D) the conversion of dihydrofolic acid to tetrahydrofolic acid
E) the conversion of PABA to tetrahydrofolic acid
A) the conversion of PABA to dihydrofolic acid
It is inappropriate to prescribe antibacterial agents to treat colds or flu because
A) these diseases are transmitted by endospores, which are hard to kill.
B) the microbes involved can develop resistance rapidly.
C) these diseases exhibit cross resistance.
D) these diseases are caused by viruses.
E) these diseases can act synergistically with each other.
D) these diseases are caused by viruses.
Which of the following statements is true of selective toxicity?
A) Selective toxicity takes advantage of structural differences between host and pathogen.
B) Antimicrobial agents must target structural differences between host and pathogen and be more toxic to the patient than the pathogen.
C) Selective toxicity takes advantage of metabolic differences between host and pathogen.
D) To be effective, an antimicrobial agent must be more toxic to the patient than the pathogen.
E) Selective toxicity takes advantage of structural and/or metabolic differences between host and pathogen.
E) Selective toxicity takes advantage of structural and/or metabolic differences between host and pathogen.
Antimicrobials that block protein synthesis by binding to the mRNA are A) beta-lactams. B) antisense nucleic acids. C) macrolides. D) aminoglycosides. E) nucleic acid analogs.
B) antisense nucleic acids.
