chemical agents in microbial control

Question 1

who first used phenol

Answer 1

joseph lister

Question 2

does phenol sterilze

Answer 2

no

Question 3

if it doesn’t sterilize, what does phenol do

Answer 3

disinfects and antisepsis

Question 4

T or F: phenol is used today

Answer 4

false; it is not used today

Question 5

why isn’t phenol used today

Answer 5

it irritates the skin and has a bad odor

Question 6

what is used today instead of phenol

Answer 6

derivatives of phenol, called phenolics

Question 7

how are phenolics formed

Answer 7

formed by the addition of an organic group or halogen to phenol

Question 8

what is a bisphenolic

Answer 8

two phenolics covalently linked together

Question 9

what kind of bond joins two phenolics to form a bisphenolic

Answer 9

covalent bond

Question 10

mode of action of phenolics

Answer 10

they disrupt membranes and denature proteins

Question 11

T or F: phenolics kill mycobacterium

Answer 11

true! and not many agents can do this

Question 12

T or F: phenolics are active in the presence of organic material

Answer 12

true

Question 13

T or F: phenolics are not good for surface disinfection

Answer 13

false; they persist on surfaces for a long period of time + are commonly used in labs and hospitals

Question 14

T or F: phenolics smell good

Answer 14

false; they smell bad

Question 15

do alcohols sterilize

Answer 15

no

Question 16

if they don’t sterilize, what do alcohols do

Answer 16

disinfection and antisepsis

Question 17

what are alcohols active against

Answer 17

bacteria and fungi

Question 18

mode of action of alcohols

Answer 18

denature proteins, dissolve membrane lipids

Question 19

name the two most commonly used alcohols

Answer 19

ethanol and isopropanol

Question 20

which is better: ethanol or isopropanol. list 3 advantages of the better one

Answer 20

isopropanol is better in terms of activity against microbes, it’s less volatile, and it’s cheaper

Question 21

T or F: alcohols evaporate and react quickly

Answer 21

true

Question 22

how long should you let alcohol soak to disinfect something

Answer 22

10-15 min

Question 23

what is a tincture

Answer 23

formed when another chemical is mixed with alcohol

Question 24

T or F: tinctures work better than if the alcohol was dissolved in water

Answer 24

true

Question 25

list 4 halogens

Answer 25

I, F, Cl, Br

Question 26

mode of action for halogens

Answer 26

they oxidize cell constituents and act as protein synthesis inhibitors

Question 27

does iodine sterilize

Answer 27

no

Question 28

if it doesn't sterilize, what does iodine do

Answer 28

antiseptic

Question 29

what is iodine effective against

Answer 29

a wide range of bacteria, many spores (at high concentrations of I2), various fungi, and some viruses

Question 30

what two forms of iodine are used for medical purposes

Answer 30

as a tincture or an iodophore

Question 31

what is an iodophore

Answer 31

iodine with an organic molecule

Question 32

two advantages of iodophore

Answer 32

non staining, and it allows for a slow release of iodine so it's less irritating to the skin

Question 33

list two common commercial preparations of iodine

Answer 33

betadine and isodine

Question 34

list two forms of chlorine

Answer 34

Cl2 and ClO2

Question 35

what is Cl2 used for

Answer 35

to treat drinking water, swimming pools, and wastewater in sewage treatment

Question 36

what is ClO2 used for

Answer 36

to disinfect large spaces and it can be combined with other chemicals

Question 37

give an example of a product formed when ClO2 binds with another chemical

Answer 37

NaOCl (household bleach)

Question 38

what is the formula for household bleach

Answer 38

NaOCl

Question 39

does chlorine sterilzie

Answer 39

no

Question 40

if it doesn't sterilize, what does chlorine do

Answer 40

disinfectant

Question 41

what is chlorine effective against

Answer 41

bacteria and fungi. NOT spores

Question 42

give an example of chlorine being used at the individual level

Answer 42

halazone tablets are used to make drinking water safe

Question 43

what is bromine used for

Answer 43

to disinfect hot tubs

Question 44

why would bromine be used instead of chlorine

Answer 44

it evaporates more slowly at high temperatures

Question 45

does bromine sterilzie

Answer 45

no

Question 46

if it doesn't sterilize, what does bromine do

Answer 46

disinfects

Question 47

what is fluorine used for

Answer 47

can be used in drinking water and toothpastes

Question 48

list 3 oxidizing agents

Answer 48

peroxides, ozone, peracetic acid

Question 49

mode of action for oxidizing agents

Answer 49

release oxygen radicals that microbes are sensitive to

Question 50

give an example of a peroxide

Answer 50

hydrogen peroxide

Question 51

what is hydrogen peroxide used for

Answer 51

household cleaners, contact lenses

Question 52

does hydrogen peroxide sterilize

Answer 52

yes BUT it must be heated gaseous hydrogen peroxide

Question 53

what is heated gaseous hydrogen peroxide used for

Answer 53

used to sterilize the atmosphere and surfaces

Question 54

what is ozone used for

Answer 54

treat drinking water

Question 55

formula for ozone

Answer 55

O3

Question 56

what is peracetic acid used for

Answer 56

used in medical facilities and food processing plants to sterilize equipment

Question 57

does peracetic acid sterilize

Answer 57

yes

Question 58

what forms can peracetic acid be used in

Answer 58

liquid or vapour

Question 59

list 5 heavy metal ions that are used

Answer 59

arsenic, zinc, copper, mercury, silver

Question 60

mode of action for heavy metal ions

Answer 60

they combine with sulfur atoms present in certain amino acids that make up proteins, which denatures them

Question 61

which heavy metal ion is used as an antiseptic

Answer 61

silver

Question 62

describe the uses of silver as an antiseptic

Answer 62

can be used in surgical dressings, burn creams, catheters, clothing, and in paper

Question 63

what is copper used for

Answer 63

controls algal growth in fish tanks, swimming pools, and reservoirs. Also used on the hulls of boats

Question 64

what are copper, zinc, and mercury used for

Answer 64

used to control mildew in paint

Question 65

do heavy metal ions sterilize

Answer 65

no

Question 66

what are quaternary ammonium compounds

Answer 66

derivatives of the ammonium ion

Question 67

mode of action of quaternary ammonium compounds

Answer 67

disrupt membranes and denature proteins

Question 68

do quaternary ammonium compounds sterilize

Answer 68

no

Question 69

if they don't sterilize, what do quaternary ammonium compounds do

Answer 69

disinfect and antiseptic

Question 70

what are quaternary ammonium compounds effective against

Answer 70

bacteria, fungi, enveloped viruses

Question 71

T or F: quaternary ammonium compounds kill nonenveloped viruses

Answer 71

false; they can only kill enveloped viruses

Question 72

when might quaternary ammonium compounds be used

Answer 72

hospitals to disinfect, or as a skin antiseptic

Question 73

name two common aldehydes

Answer 73

glutaraldehyde and formaldehyde

Question 74

mode of action of aldehydes

Answer 74

forms covalent crosslinks with several organic functional groups in order to inactivate nucleic acids and denature proteins

Question 75

which functional groups will aldehydes form covalent cross links with in order to denature proteins

Answer 75

NH2 OH COOH and SH

Question 76

which form of formaldehyde is commonly used

Answer 76

formalin

Question 77

what is formalin

Answer 77

it's formaldehyde dissolved in water to make a 37% solution

Question 78

what percentage of formalin is formaldehyde? what is the remaining component

Answer 78

37%, rest is water

Question 79

what is formaldehyde used for

Answer 79

embalming + as a disinfectant for surgical instruments

Question 80

does formaldehyde sterilized

Answer 80

yes

Question 81

in what conditions can formaldehyde sterilize

Answer 81

if left for 24 hours using an 8% solution

Question 82

list some disadvantages of formaldehyde

Answer 82

potential carcinogen, long term exposure in air or on skin can lead to respiratory problems and skin irritation, produces irritating fumes and bad odor, leaves a residue

Question 83

what percentage of glutaraldehyde is used as a disinfectant

Answer 83

2%

Question 84

T or F: glutaraldehyde can kill mycobacteria

Answer 84

true

Question 85

is glutaraldehyde a sterilant

Answer 85

yes

Question 86

in what conditions is glutaraldehyde a sterilant

Answer 86

if left for 3-10 hours

Question 87

advantage of glutaraldehyde

Answer 87

non corrosive

Question 88

disadvantages of glutaraldehyde1

Answer 88

gives off irritating fumes and leaves a residue

Question 89

what is glutaraldehyde used for

Answer 89

used as a disinfectant for lab and hospital equipment

Question 90

give an example of a gaseous agent

Answer 90

ethylene oxide

Question 91

what is ethylene oxide effective against

Answer 91

all bacteria and bacterial spores, but requires a lengthy exposure time

Question 92

mode of action of ethylene oxide gas

Answer 92

cross links functional groups in proteins and nucleic acids

Question 93

T or F: to be a sterilant, ethylene oxide gas requires a lengthy exposure time

Answer 93

true

Question 94

uses of ethylene oxide gas

Answer 94

hospitals and dental offices (gas autoclave), can be used to treat heat sensitive materials

Question 95

3 advantages of ethylene oxide gas

Answer 95

sterilizing, highly penetrating, and it sterilizes without heat

Question 96

4 disadvantages of ethylene oxide gas

Answer 96

highly explosive, poisonous, carcinogen, takes a long exposure time to treat items

Question 97

list 3 biological methods of control

Answer 97

predacious bacteria bacteriophages products of microorganisms (ie bacteriocins)

Question 98

what agents can kill mycobacterium

Answer 98

phenols, glutaraldehyde

Question 99

which agents sterilize

Answer 99

heated gaseous hydrogen peroxide, peracetic acid, formaldehyde, glutaraldehyde, ethylene oxide gas