Microbiology CH 7Written Exam Questions Correctly Answered.
Which of the following shows the moist heat methods in order of the temperature used
... [Show More] (highest to lowest)? - CORRECT ANSWER Ultrahigh>Autoclave>Boiling>Batch Pasteurization
_______________ is a process used to destroy pathogens in food and drinks. It must be done at a lower temperature than other methods so that _______________. - CORRECT ANSWER Pasteurization; the taste of the food or drink will not be altered
During a flood, a community's well water system is contaminated with a pathogenic fungus. If the residents boil their water for 15 minutes prior to consumption, will they be protected? - CORRECT ANSWER yes, most likely
Prior to drawing blood for a blood donation, the nurse will scrub the arm with a Betadine solution. This form of antimicrobial control would be called __________. - CORRECT ANSWER Antisepsis
Antisepsis is the destruction of vegetative pathogens on living tissue
When microbial control methods are used, microbes are destroyed at a constant rate; there is no instantaneous death of all the microbes present. That microbial death rate is influenced by all of the following factors EXCEPT __________. - CORRECT ANSWER toxins produced by the microbe
Although microbial toxins may influence the status of an infection, these factors do not influence the death rate of the organism.
Microbial control methods usually target any of the following microbial structures EXCEPT which one? - CORRECT ANSWER mitochondria
Most of the target organisms are bacteria or viruses, which do not contain mitochondria. In addition, microbial control mechanisms attempt to target structures in microbes that are not common to human cells.
Which of the following physical methods of microbial control denatures proteins as a mechanism of action? - CORRECT ANSWER boiling or autoclaving
Heat denatures proteins by altering the tertiary structure, inhibiting their function.
Gluteraldehydes are among the most effective chemical control agents because they __________. - CORRECT ANSWER are relatively safe, yet considered a sterilizing agent
Even in small concentrations, given adequate exposure time, gluteraldehydes inactivate microbial proteins and are considered bactericidal, tuberculocidal, virucidal, and sporicidal while being less irritating to living tissue. The fact that it is a liquid makes it an extremely versatile agent for a variety of hospital equipment.
Contaminated hospital equipment represents a difficult environment to control harmful microbial growth. Regarding influences that affect disinfection of hospital equipment, which of the following is an accurate statement? - CORRECT ANSWER The cell wall of gram-negative bacteria is especially resistant to many chemicals that are used destroy microbes.
A principal factor in this relative resistance to biocides is the external lipopolysaccharide layer of gram-negative bacteria.
Consider various effects of moist and dry heat to control microbial growth. Which of the following methods would best reduce microbes without altering the taste and chemical composition of beer? - CORRECT ANSWER pasteurization
Pasteurization retains the properties of the alcohol and the protein structure. Although it does not destroy all microbes, it is adequate to destroy most of the harmful microbes while retaining flavor.
Surface-active agents act by decreasing surface tension so that microbes can be more easily removed. All of the following agents use this mechanism of action EXCEPT __________. - CORRECT ANSWER halogens
This is the exception. The mechanism of action for halogens includes inhibiting proteins and acting as a strong oxidizing agent, but halogens do not act as surface-active agents.
Evaluate the following chemical agents in regard to the effective use against endospores and mycobacteria. In a clinical situation where it is essential to control microbial growth that includes both mycobacteria and endospores, which chemical agent would be the most effective to guarantee the broadest disinfection? - CORRECT ANSWER chlorines
Chlorine has the best overall action against both of these targets. [Show Less]