Microbiology - Chapter 11 Physical And Chemical Control Of Microbes (Test 4)

Front 1

what's the fastest way to kill endospores/sterilize?

Back 1

pressure plus moist heat

Front 2

what is Pasteurization used for?

what wouldn't you use it for?

Back 2

to disinfect beverages

To kill endospores or thermoduric microbes

Front 3

Does boiling water sterilize?

how long must you boil to achieve disinfection

Back 3

no, it disinfects

30 minutes

Front 4

when is dry heat (Hot Air and Incineration) used?

Back 4

Common practice in microbiology lab- incineration on inoculating loops and needles using a Bunsen burner

Front 5

when is a dry oven used?

Back 5

Used for heat-resistant items that do not sterilize well with moist heat

Front 6

Describe the use of cold and disiccation

Back 6

Used to slow growth of cultures and microbes in food during processing and storage
Cold does not kill most microbes; freezing can actually preserve cultures

Front 7

define dessication

define lyophilization

Back 7

Desiccation: dehydration of vegetative cells when directly exposed to normal room air
Lyophilization: a combination of freezing and drying; used to preserve microorganisms and other cells in a viable state for many years

Front 8

which forms of radiation are used to control microbes?

Back 8

Gamma rays - most potent
X rays
Ultraviolet radiation

Front 9

which is the most damaging form of radiation for us?

describe it.

Back 9

ionizing radiation, i.e. gamma rays

if the radiation ejects orbital electrons from an atom causing ions to form

Front 10

what are three types of ionizing radiation?

Which is most and least penetrating?

Back 10

Gamma rays, most penetrating;
X rays, intermediate;
cathode rays, least penetrating

Front 11

what is nonionizing radiation ultraviolet rays used for?

Back 11

Usually disinfection rather than sterilization
Powerful tool for destroying fungal cells and spores, bacterial vegetative cells, protozoa, and viruses

Front 12

what are some application for ionizing radiation?

Back 12

Food products
Medical products

Front 13

what is a physical method of removing microbes from air and liquids?
examples?

Back 13

filtration
Water purification and liquids that can't withstand heat.
Removing airborne contaminants (HEPA filters

Front 14

define tinctures

Back 14

Tinctures: solutions dissolved in pure alcohol or water-alcohol mixtures

Front 15

what are the Factors that Affect the Germicidal Activity of Chemicals?

Back 15

Nature of microorganisms being treated
Nature of the material being treated
Degree of contamination
Time of exposure
Strength and chemical action of the germicide

Front 16

what are some examples of halogen antimicrobials

Back 16

Fluorine, bromine, chlorine, and iodine

Front 17

would you use a halogen for killing endospores?

Back 17

Yes, the are Microbicidal and sporicidal with longer exposure

Front 18

what is an example of the halogen chlorine? what does it do?

Back 18

Household bleach
Kills bacteria and endospores
Also kills fungi and viruses

Front 19

what halogen would you use to apply topically to disinfect an area?

Back 19

Kills bacteria and endospores
Also kills fungi and viruses

Front 20

what is the action of phenol and its derivatives?

Back 20

High concentrations: cellular poisons
Lower concentrations: inactivate certain critical enzyme systems

Front 21

what is chlorhexidine used for?

Back 21

At moderate to high concentrations, it is bactericidal for both gram-positive and gram-negative bacteria but inactive against spores
Used commonly in mouthwash
ie. Chloroseptic

Front 22

what is the minimum concentration that alcohol must be to be effective?

Back 22

at least 50%

Front 23

would you use alcohol against a non-enveloped virus?

Back 23

no, alcohols are More effective in inactivating enveloped viruses than non-enveloped viruses

Front 24

what is the mechanism of action of hydrogen peroxide?

Back 24

Oxygen forms hydroxyl free radicals which are highly toxic and reactive to cells
Bactericidal, virucidal, and fungicidal

Front 25

could you use hydrogen peroxide against endospores?

Back 25

Yes, in high concentration

Front 26

what are the mechanisms of action of alcohols

Back 26

mostly dissolution of membrane lipids, denaturation of proteins and dehydration

Front 27

what type of detergents do you want to use to disinfect surfaces?

Back 27

Cationic detergents are more effective because the positively charged end binds well with the predominantly negatively charged bacterial surface proteins

Front 28

Soaps are _______microbicides but gain germicidal value when mixed with agents such as ______ or _______

Back 28

weak
chlorhexidine or iodine

Front 29

define oligodynamic action

Back 29

Oligodynamic action: having antimicrobial effects in exceedingly small amounts

Front 30

what is the antimicrobial mechanism of action of heavy metal compound

Back 30

Bind onto functional groups of proteins and inactivating them (metals are catalysts)

Front 31

what are the drawbacks to using metals in microbial control?

Back 31

Can be very toxic to humans
Large quantities of biological fluids and wastes neutralize their actions
Microbes can develop resistance to them

Front 32

what germicide has a -CHO functional group on the terminal carbon?

Back 32

–CHO functional group on the terminal carbon

Front 33

examples of gaseous sterilants and disinfectants

Back 33

Ethylene oxide (ETO)
Propylene oxide
Chlorine dioxide

Front 34

what is the Primary source of certain drugs used in chemotherapy
what is their limitation?

Back 34

dyes
Limited applications because they stain and have a narrow spectrum of activity

Front 35

why are acids and alkalis limited in applications?

Back 35

Limited in applications due to their corrosive, caustic, and hazardous nature