micro ch 7.txt

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  1. Sterilization is the _______ or __________ of ___ ______ _________.
    removal; destruction; all living organisms
  2. What is most common method of killing microbes, even the most resilient ones?
  3. What is a sterilizing agent called?
  4. What is the term used for destroying the endospores of Clostridium botulinum in food? 
    Commercial Sterilization
  5. Control directed at destroying harmful microorganisms is called ____________.
  6. Disinfection is usually aimed at the destruction of __________ _______________________ pathogens, which is not the same thing as sterility.
    Vegetative (non-endospore-forming)
  7. What is the term for the killing of harmful bacteria on LIVING tissue?
  8. The process of _________ _____________, which mostly results in the _________ _______, rather than the killing, of most of the microbes in a limited area.
    Degerming (degermation); mechanical removal
  9. What is the process of lowering micrbial counts on cups or eating utensils to safe public health levels and minimize the chances of disease transmission from one user to another?
  10. A _______, or _________, killls microorganisms (usually with certain exceptions, such as endospores)
    Biocide; germicide
  11. To inhibit the growth and multiplication of bacteria is called what?
  12. ______ indicates bacterial contamination. 
  13. What is the absence of significant contamination? 
  14. What are the factors that infuence the effectiveness of antimicrobial treatments?
    • Microbe Count
    • Environmental Influences (organic matter, biofilms, etc.) 
    • Exposure Time
    • Microbial Characteristics
  15. How do microbial control agents act?
    • Alteration of membrane permeability
    • Damage to Proteins
    • Damage to Nucleic acids
  16. What is Thermal Death Point (TDP)?
    The lowest tmperature at which all the microorganisms in a particular liquid culture will be killed in 10 minutes
  17. The thermal death time (TDT) is the _______ length of time for ___ bacteria in a particular liquid culture to be ______ at a _____ ___________. 
    minimal; all; killed; given temperature
  18. Decimal reduction time (DRT, or D value) is the ____, in _______, in which __% of a population of bacteria at a given temperature will be killed. 
    time; minutes; 90%
  19. Moist heat kills microorganisms primarily by ___________ proteins (____________), which is caused by ________ of ________ _____ that hold the proteins in their three-dimensional structure.
    coagulating; denaturation; breaking; hydrogen bonds 
  20. One type of moist heat "sterilization" is _______, which kills __________ forms of bacterial pathogens, almost all _______ and _____ and their spores in about 10 minutes.
    boiling; vegetative; viruses; fungi
  21. Autoclaving conditions are ___ degrees Celsius at __ psi for __ minutes. 

    What is autoclaving used to sterilize? 
    121; 15; 15

    Culture media, instruments, dressings, intravenous equipment, applicators, solutions, syringes, transfusion equipment, and numerous other items that can WITHSTAND HIGH TEMPERATURE AND PRESSURE!!!
  22. Pasteurization is the ___________ of all__________ microbes. 
    elimination; pathogenic
  23. Define thermoduric.
  24. Name two forms of Dry Heat Sterilization and how it kills microbes.
    Direct flaming and hot-air sterilization. Dry Heat Sterilization kills by oxidation effects.
  25. What is filtration used to sterilize?
    Heat sensitive materials such as some culture media, enzymes, vaccines, and antibiotic solutions. 
  26. Low temperatures have a ______________ effect on bacteria. 
  27. What is desiccation?

    How does this effect bacteria?
    The absence of water.

    Microorganisms cannot grow or reproduce but can remain viable for years in the absence of water. 
  28. Ionizing radiation - gamma rays, X rays, or high-energy electron beams - has a wavelength _______ than that of non-ionizing radiation., less than about 1 nm.
  29. Nonionizing radiation has a waveleng ______ than that of ionizing radiation, usually greater than about 1 nm. 
  30. How does radiatin affect microbes?
    By targeting organic cellular components, particularly DNA. 
  31. How do phenols and phenolics affect bacteria?
    By injuring lipid-conntainng plasma membranes, which results in leakage of cellular contents.
  32. Iodine impairs _______ _________ and alters ____ _________. 
    protein synthesis; cell membranes
  33. Alcohols effectively kill ________ and _____ but not __________ and ____________ _______. 
    bacteria; fungi; endospores; nonenveloped viruses
  34. How do alcohols kill microbes? 
    They cause coagulation of a layer of protein under which bacteria continue to grow. 
  35. What is oligodynamic action,what exhibits it, and how does it kill microbes?
    Oligodynamic action is a antimicrobial activity that is exhibited by metal solutions, and it kills microbes by denaturing their proteins.
  36. Quats are cationic detergents attached to ____ and allow cytoplasmic constituents to leak out of the cell by __________ ______ _________. 
    NH4+; disrupting plasma membranes
  37. Carboxylic acids inhibit ______ __________ and are used as ____ _____________. 
    fungal metabolism; food preservatives
  38. Aldehydes such as formaldehyde and glutaraldehyde exert their antimicrobial effect by ____________ ________ and are amoung the ____ effective chemical disinfectants.
    inactivating proteins; most
  39. ________ _____ is the gas most frequently used for sterilization. 
    Ethylene oxide
  40. Ethylene oxide penetrates most materials and kills all microorganisms by _______ ____________. 
    protein denaturation
  41. What are free radicals in plasma gases used to sterilize?
    Plastic instruments
  42. Supercritical fluids, which have properties of liquid and gas, con sterilize at ___ temperatures
  43. Hydrogen peroxide, peractic acid, benzoyl peroxide and ozone exert their mantimicrobial effect by _________ molicules inside cells.
  44. Gram-negative bacteria are generally  ____ resistant than gram-positive bacteria to disinfectants and antiseptics.
  45. Mycobacteria, endospores, and protozoan cysts and oocyst are ____ _________ to disinfectant and antiseptics. 
    very resistant
  46. nonenvelooped viruses are generally ____ resistant than enveloped viruses to disinfectants and antiseptics. 
  47. Prions are _________ to disinfection and autoclaving
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micro ch 7.txt
2012-11-07 18:24:58
Microbiology chapter

Microbiology Chapter 7
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