Ch 9 Controlling Microbial Growth in the Environment

Question 1

What is sterilization?

Answer 1

remove all living cells and viruses

Question 2

What is commercial sterilization?

Answer 2

Kills only harmful microbes

Question 3

What is aseptic?

Answer 3

No microbe contamination, only normal organisms

Question 4

What is disinfection?

Answer 4

Physical/Chemical agents to treat objects

Question 5

What is antisepsis?

Answer 5

Antiseptics to clean skin/tissue

Question 6

What is degerming?

Answer 6

remove microbes form surface by scrubbing

Question 7

What is sanitization

Answer 7

Disinfect according to public standards

Question 8

What is pasteruization?

Answer 8

Heat to kill pathogens & reduce spoilage

Question 9

Define the suffix -statis/-static

Answer 9

Slow/inhibit growth

Question 10

Define the suffix -cide/-cidal

Answer 10

Kills the microbe

Question 11

What happens if you alter the cell wall/membrane?

Answer 11

Cells burst and content leaks out

Question 11

What happens if you damage proteins & nucleic acids?

Answer 11

Denature proteins, destroy DNA/RNA

Question 11

What does a high level germicide kill?

Answer 11

All pathogens & endospores

Question 12

What does a intermediate level germicide kill?

Answer 12

All pathogens but endospores

Question 12

What does a low level germicide kill?

Answer 12

vegetative bacteria, fungi, protozoa, some virus (no cyst & spore)

Question 12

What germicide would you use in a BSL 1 lab?

Answer 12

Low level

Question 13

What germicide would you use in a BSL 2 lab

Answer 13

Intermediate level

Question 14

What germicide would you use in a BSL 3 or 4 level?

Answer 14

High level

Question 15

What characteristic defines the relative susceptibility of prions, endospores, and mycobacteria?

Answer 15

Prions: misfolded proteins
Endospores: thick protective coat
Mycobacteria: mycolic acid

Question 16

What characteristic defines the relative susceptibility of cysts and active protozoa?

Answer 16

Cysts: have shell.
Active protozoa: no shell.

Question 17

What characteristic defines the relative susceptibility of small non enveloped viruses, large non enveloped viruses, and enveloped viruses?

Answer 17

Small: less surface area.
Large: more surface area
Enveloped: phospholipid membrane

Question 18

What characteristic defines the relative susceptibility of fungal spores and vegetative fungi?

Answer 18

Fungal spores: protein shells
Vegetative fungi: No shell

Question 19

What characteristic defines the relative susceptibility of gram-negative and gram-positive bacteria?

Answer 19

Gram-Pos: No protein pumps
Gram-Neg: Has protein pumps

Question 20

What is a phenol coefficient?

Answer 20

Eval efficacy of disinfectants & antiseptics (<1 = effective)

Question 21

What is the Use-Dilution test?

Answer 21

How much to dilute and still be effective

Question 22

What is the Kelsey-Sykes Capacity test?

Answer 22

How long does it take to destroy or if it destroys?

Question 23

What is the in-use test?

Answer 23

Eval. effectiveness on surface of object

Question 24

How does heat control microbial growth?

Answer 24

denature protein, disrupt cytoplasmic membrane, cell wall, and nucleic acid

Question 25

What is thermal death point?

Answer 25

Lowest temp to destroy all cells

Question 26

What is thermal death time?

Answer 26

Time to destroy all cells

Question 27

What is decimal reduction?

Answer 27

Time to destroy 90% of cells

Question 28

What is moist heat?

Answer 28

Using boiling H20 to kill cells

Question 29

What is more effective, dry or moist heat? Why?

Answer 29

Moist, H20 is a better heat conductor

Question 30

T/F H20 boils at a lower temp at higher elevation

Answer 30

True

Question 31

T/F Boiling temp. increases as pressure increases

Answer 31

True

Question 32

What is pasteurization ?

Answer 32

Used in food, not sterilization

Question 33

Why would dry heat be used if it isn't effective?

Answer 33

things that can't be sterilized w/ moist heat

Question 34

How does refrigeration/freezing control microbial growth?

Answer 34

Cold slows metabolism, growth, and reproduction.

Question 35

How does desiccation inhibit microbial growth?

Answer 35

Drys out moisture

Question 36

How does lyophilization inhibit microbial growth?

Answer 36

freeze dry to preserve culture

Question 37

How does filtering inhibit microbial growth?

Answer 37

Sieve catches microbe

Question 38

How does osmotic pressure control microbial growth?

Answer 38

Hypertonic environments inhibit growth

Question 39

How does radiation control microbial growth?

Answer 39

Ionizing radiation: ions denature mol. Non ionizing: change shape of proteins and nucleic acid

Question 40

How do phenol and phenolics impact microbial growth?

Answer 40

-Mid- low lvl. -Denatures proteins/cell membrane -good in organic matter

Question 41

How does alcohol impact microbial growth?

Answer 41

-Mid lvl. -Denature protein/cytoplas. mem

Question 42

How do halogens impact microbial growth?

Answer 42

-Mid lvl. -Denature enzymes

Question 43

How do oxidizing agents impact microbial growth?

Answer 43

-High lvl -Oxidize microbial enzymes

Question 44

How do surfactants impact microbial growth?

Answer 44

-Degerming, not antimicrobial -Quats disrupt cell membrane

Question 45

How do heavy metals impact microbial growth?

Answer 45

-low lvl -ions denature proteins

Question 46

How do aldehydes impact microbial growth?

Answer 46

-Cross-link structures not normally connected -Denature protein/inactive nucleic acid

Question 47

How do gaseous agents impact microbial growth?

Answer 47

-Cross-link structures not normally connected -Denature protein/inactive nucleic acid

Question 48

How do enzymes impact microbial growth?

Answer 48

-act against microorganisms

Question 49

How do antimicrobials impact microbial growth?

Answer 49

-Treatment of disease