Chapter 7

Question 1

disinfection

Answer 1

reducing the number of pathogenic organisms on objects or in materials so that they pose no threat of disease

Question 2

sanitization

Answer 2

to remove microbes or reduce their populations to a safe level as determined by public health standards

Question 3

sterilization

Answer 3

killing of all microorganisms, including bacterial spores

Question 4

antiseptics

Answer 4

chemical agents that can be used safely on skin and tissues to destroy microbes or inhibit their growth

Question 5

alcohol

Answer 5

damages membrane and denatures proteins
not effective against spores
used in many hand sanitizers

Question 6

phenols

Answer 6

denature proteins

causes damage to skin - not used

Question 7

bisphenols

Answer 7

derivative of phenol - two phenols together

used instead of phenol

Question 8

halogens

Answer 8

oxidize proteins

e.g. chlorine

Question 9

iodine

Answer 9

modifies proteins

used as antiseptic on wounds and in surgery

Question 10

iodophors

Answer 10

release iodine over a long period of time and don’t stain

e.g. Wescodyne

Question 11

ethylene oxide gas

Answer 11

alkylation - throw alkyl groups onto protein to deactivate them

Question 12

hydrogen peroxide

Answer 12

antiseptic rinse for wounds and scrapes
catalase in tissue breaks it down into oxygen, which acts against anaerobes
bubbling loosens dirt and dead tissue

Question 13

dyes

Answer 13

modifies nucleic acid

e.g. crystal violent - skin antiseptic

Question 14

formaldehyde and glutaraldehyde

Answer 14

alkylation - denatures proteins and nucleic acids

Question 15

phenol coefficient

Answer 15

determines effectiveness of a chemical agent as a disinfectant compared to phenol (the gold standard)
higher than 1 - better than phenol

Question 16

high level disinfectant

Answer 16

destroys all microbes, but not all spores

Question 17

intermediate level disinfectant

Answer 17

destroys all vegetative bacteria including mycobacteria (TB bacterium), fungi, and most viruses

Question 18

low level disinfectant

Answer 18

destroys fungi, vegetative bacteria except mycobacteria, and some viruses

Question 19

autoclave

Answer 19

physical sterilization agent 
uses steam to kill 
temp: 121.5°C
pressure: 15 lbs/in2
time: 15 mins

Question 20

autoclave - flash cycle

Answer 20

temp: 134°C
pressure: 30 lbs/in2
time: 3 mins

Question 21

Geobacillus stearothermophilus

Answer 21

gold standard used for autoclaves - toughest spores

Question 22

disadvantages of autoclave

Answer 22

damage to plastic and rubber items
corrodes metal items
may leave water deposits, may be wet

Question 23

dry heat oven

Answer 23

physical sterilization agent

temp: 160°C
time: 2 hours

Question 24

advantages of dry heat oven

Answer 24

no corrosion
low cost
items are dry

Question 25

disadvantages of dry heat oven

Answer 25

long
damage to plastic and rubber items
can’t sterilize liquids

Question 26

pasteurization

Answer 26

physical agent - kills potential pathogens in milk, especially TB bacterium
heat milk - 62°C for 30 mins

Question 27

flash pasteurization

Answer 27

72°C for 15 seconds

Question 28

UV radiation

Answer 28

creates thymine dimers

Question 29

X-ray radiation

Answer 29

produces free radicals - destroy DNA

Question 30

filtration

Answer 30

for liquids

to get rid of pyrogens (LPS lipid A) as well as sterilize