Exam 2 Flashcards
Lipid envelope is much more sensitive to….
Disinfectants
Which of the following would not sterilize;
Ionizing radiation, ethylene oxide, alcohol, autoclave, all of the above?
Alcohol
Cell wall inhibiting antibiotics block the synthesis of new cell wall formation such that growing bacteria will not complete the walls. Based on this idea at what point in the bacterial growth curve are the bacteria the most vulnerable to these bacteria antibiotics? Lead phase, lag phase, log phase, stationary phase decline phase
Log phase
An organism that expends energy to grow in a habitat with low water activity and high solute activity in order to maintain internal solute concentrations to retain water is: acidophile, neutrophile, osmotolerant, aerotolerant anaerobe, pyscroophile.
Osmotolerant
Sweetly and salty foods wouldn’t require refrigeration to prevent spoilage because they are ___________?
A. Insufficient nutrients B. Low ph C. Low water activity D. Toxic alkaline Chemicals E. Naturally occurring antibiotics
C. low water activity
A(n) _________ is used to prevent infection by killing or inhibiting pathogen growth on animal tissues.
Antiseptic
Which of the following does not apply to phenols?
A. It is the standard disinfectant against which others are evaluated (ie phenol coefficient).
B. It’s activity is not reduced in the presence of organic matter.
C. It has a sweet smell and no detrimental effects on the skin.
D. It acts by disrupting membranes and denaturing proteins.
C. It is a sweet….
Which of the following has it beta-lactam ring? Macrolide Tetracyclines Quinolones Aminoglycosides Penicillins
Penicillins
This antibiotic does not target the linking of Peptidoglycan subunits into the growing cell wall but inhibits a different part of cell wall synthesis pathway. Bacitracin Ampicillin .P. Vancomycin .N. Methicillin .P. Ciprofloxin (cephelasporin)
Bacitracin
In general when using chemical disinfectants to inactivate viruses or limit their transmission
A. Naked viruses are more tolerant to chemical disinfectants. Yes
B. Envelope viruses are more tolerant to chemical disinfectants. No
C. Naked viruses and envelope viruses are equal in their tolerance to disinfectants
A
Bacteria that grow at the surface in bodies of water would be considered... An aerobe Aerotolerant An obligate anaerobe Capnophiles An alkalophic
An aerobe
Gram-negative organisms are often _______ to chemical disinfectants then gram-positive organisms due to the presence of an outer membrane Porins and LPS.
Less susceptible
Both zanamivir and islet amicus are neuramidase inhibitors which block the function of influenzae protein neuramidase. These drugs would... Prevent viral attachment Blocking viral penetration Blocking viral polymerase Slowing viral release Causing mutations in viral genome
Slowing viral release
Heavy metals generally kill microorganisms by…
Uniting with water molecules and dehydrating the microorganism.
Reacting with sulfhydryl groups of proteins and binding them together.
Penetrating the lipids microbial cytoplasm
Inhibiting flagellar motion in the microorganism
Reacting with Sulfhydryl groups of proteins and binding them together
The chemical Counterpart of the autoclave uses... A. Mercury oxide in a closed chamber B. Iodine in an iodophor solution C. Phenol in the form of cresol D. Ethylene oxide with an inert gas
Look up answer
Sulfanilimide works by competitive inhibition and blocks... A. The effects of B-lactam antibiotics B. tRNA entry into the ribosome C. Mycotic acid synthesis D. Formation go frolic acid
B.
Beta lactam antibiotics function by…
A. Blocking the translocation of the ribosome along the mRNA
B. Interacting with RNA polymerase and inhibiting transcription initiation
C. Blocking the transport of peptidoglycan across the cell membrane.
D. Blocking the function of topoisomerase
E. Interacting with transpeptidases, inhibiting the cross-linking of cell wall
E.
Isoniazid is of particular value…
A. For determining the MIC of a drug
B. For performing the Kirby Bauer test
C. For separating gram-positive and gram-negative bacteria
D. For treating tuberculosis caused by mycobacteria
D.
If you were cleaning benches or tables on which you would be placing patients with exposed skin you would probably want to use a disinfectant such as _________.
Alcohol
Which of the following disinfectants should be used if high concentrations of organic matter are present around the contamination.
Alcohols halogens phenols or heavy metals
Phenols
During the anthrax scare the Postal Service needed a good means to sterilize mail without harming it. In order to do this they needed a chemical that they can easily penetrate through the seems of an envelope and is capable of destroying spores (ie sterilization) which of the following chemicals might be a good candidate.
Phenol’s heavy metals isopropanol ethylene oxide UV radiation
Ethylene oxide
Which of the following would kill the greatest percentage of cells?
A D100 value of 10 minutes
A D100 value of 5 minutes
Both would kill the same percentage of cells
Both would kill the same percentage of cells
Which of the following chemical disinfectants would not disrupt cell membranes…
Cationic detergents, phenolic compounds, 70% alcohol, heavy metals, all of these disrupt membranes
Heavy metals
Some antiviral drugs block pH dependent entry mechanisms used by viruses, which viruses would most likely be impacted by this drug?
Naked viruses, envelope viruses, bacteriophages, plant viruses
Envelope viruses
