Micro Ch 7 Test questions – Flashcards
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| after 7 days the dry weight of fungi on 'apples' is 5mg, you conclude... |
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| the compound is fungistatic |
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| decimal reduction time is the |
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| time in minutes that 90% of pupulationat a given temp is gone |
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| sterilization is |
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| removal of all microorganisms |
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| difference between a disinfectant and an antiseptic |
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| disinfectans are used on envir suf and antiseptics are used on living tissue |
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| what treatment achieves sterilization |
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| autoclaving |
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| name 3 antiseptics... 1 not |
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| iodine, bisphenol, alcohol are-soap is not (all are used on skin) |
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| why is soap not ann antiseptic |
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| because soap does not kill or inactivate microbe |
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| what kills cells by damaging dna? |
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| uv |
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| what condition would interfere with the effectiveness of an antiseptic or disinfectant |
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| presence of biofilms |
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| what is typically destroyed by antimicrobial agents (3 target agents) |
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| plasma membranes, proteins, nucleic acids |
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| what are these not? lyophilization, deep-freezing filtration |
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| bacterialcidal |
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| what substance is effective against bacterial endospores |
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| chlorine bleach |
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| what is th most effect conc of ethyl slcolhol? |
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| 75% |
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| what organism is the most difficult to kill |
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| prions |
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| is triclosan an oxidizing agt? |
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| No Oozone, hydr pero, chlorine) |
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| what is the most useful disinfectant for med instruments |
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| glutaraldehyde.. |
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| Iodine is considered a ? |
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| antiseptic (betadine) |
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| which organisms is generally easy to kill |
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| lipophilic viruses |
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| if the disinfectants are nontoxic and designed for the same purpose what is the most effect? |
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| z-1:1,000.. the disinfectant with the greast use-dilution value |
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| disk-diffusion test 'which gives the best dilution... |
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| not enough info |
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| why does dairy creamer etc not have to be refridg? |
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| IT IS TREATED WITH.....UHT treatment, ultra high temp |
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| antiseptic is used to remove microbes from |
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| the skin before an injection |
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| what agent challenges sterilization |
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| prions |
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| what is the term for inhibiting growth |
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| bacteriostatic |
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| what is not a major target for antimicrobials |
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| flagella |
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| what treatment is most effective against the contaminated counter |
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| heat, 52C |
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| what are char of autoclave |
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| use of moist heat, high pressures, high temp, ability to sterilize solu w/endospores |
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| pasteurization was first used by pasteur to control spoilage of |
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| wine |
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| what i sappropriat for a medium for growing fasidious bacteria? |
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| autoclave the medium pror to adding growth factors, cool, aseptically add the growth factors |
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| what is least likely to NOT be damaged by gamma radiation |
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| prions |
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| name food preservation methods |
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| deep freezing, osmotic pressure, commercial canning, dessication |
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| what is the easiest to kill with microbial agents? |
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| e.coli |
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| what radiation is least effective in killing microbes |
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| microwave |
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| DRT for a part bact spe at 60C is 30 mins, how long would it take at this temp to ___ bacterial pop |
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| 90 minutes |
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| alcohol is most effective at what % |
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| 70% |
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| examples of microbial control with heavy metal... (4) |
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| algae control in pools with copper sulfate, burn treat w/silver sulf, mouthwash w/zinc chloride, antiseptic sol containg mercurochrome (NOT benzol peroxide) |
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| a compound found in antimicrobial soaps that targets g-pos bact.. |
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| triclosan |
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| list possibilities of additives in snack food |
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| (xanthan is not) pot sorbate, sodium benz, calc prop, sorbic acid |
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| Most viruses are highly resistant to disinfectant and antiseptics, t or f |
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| false |
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| presence of organic matter such as blood or saliva may impair the action of antimicrobial chem t or f |
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| t |
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| all bacteria die at once when they are exposed to heat or chem treat t or f |
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| f |
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| times reeq for sterilization in an autoclave are shorter than those req in a dry oven because moist specimens mor effec than does dry heat (t or f) |
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| t |
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| ethylene oxide gas is used to sterilize medical equip that might be damaged by exp of others |
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| t |
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| tor f, uv radiation and xray rad are similar in that they damage dna and have a high penetrating power |
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| f |
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| iodine is one of the least eff antimicrobial chem, effec only agains certain very sensitive t or f |
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| f |
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| ionizing radiation can be used to sterilize some foods such as spices, meat, and fruits and veget t or f |
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| t |
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| oxidizing agents limit the growth of |
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| anaerobic bact |
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| 4 types of bacteria may survive pasteurization they are.... |
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| thermoduric, endospore, heat resistant |
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| ___ ammonium cmpds are less effective against g-neg bacteria and more efficient with g-pos |
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| quaternary |
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| what term inhibits growth |
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| homeostatic |
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| if an agent is fungistatic it is?? |
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| it would slow growth as the treatment |
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| what household substance is effective against endospores |
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| chlorine bleach |
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| This chemical is not an ooxidizing agent, it inhibits enzyme req for synthesis of lipids |
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| triclosan |
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| name a couple of oxidizing agents |
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| chlorine, hydrogen peroxide, ozone |
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| what is the order of death for these bacteria by chemical agentsg positive and negative, endospores, mycobacteria |
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| g pos g neg, mycobacteria, endospores |
