Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology > Chapter 9- Controlling Microbial Growth > Flashcards

Chapter 9- Controlling Microbial Growth Flashcards

1
Q

Static

A

inhibits growth but does not kill the microbe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Cidal

A

kills the microbe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Sterilization

A

The removal of all microorganisms, including endospores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Disinfection

A

A chemical treatment to kill/inhibit growth on inanimate objects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Degerming

A

The mechanical removal of most of the microorganisms in a limited area by scrubbing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Sanitation

A

Reducing the # of pathogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Aseptic

A

Free of contamination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

2 ways the microbial control agents kill or inhibit the growth of microorganisms:

A
  1. Alteration of cell walls/plasma membrane
  2. Damaging proteins/DNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Alteration of cell walls/plasma membrane:

A

Disrupts osmosis and/or allows cellular contents to leak out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Damaging proteins/DNA

A

Denatures the shape of proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Factors to select the most appropriate antimicrobial:

A
  • Harmless to humans
  • Effectiveness
  • Susceptibility of microbe (the bacteria must be susceptible to it)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Physical Methods of Microbial control

A
  1. Moist Heat
  2. Dry Heat
  3. Low Temperature
  4. Desiccation
  5. Filtration
  6. Osmotic Pressure
  7. Radiation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Moist Heat

A

Denatures proteins and disrupts cell membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Methods within moist heat

A
  • Boiling
  • Autoclaving
  • Pastureization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Boiling

A
  • Type of moist heat sterilization
  • Kill pathogens and almost all viruses in 10 min
  • Less effective on destroying endospores
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

At sea level, water boils at

A

100 C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Autoclaving

A
  • Uses pressure per square inch (psi)
  • Used to sterilized culture media and surgical equipment
  • Gets rid of endospores
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Pasteurization

A
  • Kills pathogenic bacteria and most nonpathogens
  • Many heat-resistant bacteria survive pasteurization but are nonpathogenic
  • NOT sterilization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Dry Heat

A

Requires higher temps for often longer time periods compared to moist heat

20
Q

Types of dry heat:

A
  • Direct Flaming
  • Hot-air Sterilization
  • Incinerator
21
Q

Direct Flaming

A
  • Used to sterilize inoculating loops and needles
  • ex: bunsen burner
22
Q

The Bunsen burner achieves a temp of

A

1500 C

23
Q

Hot-air Sterilization

A
  • Placed in oven for 2 hours
  • Used to sterilize empty glassware
24
Q

Incinerator

A

Can achieve temperatures of 850C for as little as 2 seconds

25
Q

Low Temperature
& important exception

A
  • Refrigeration temperatures will slow bacterial growth and metabolism
  • Bacteriostatic effect (will not kill, only inhibit)

Important exception: Listeria monocytogenes

26
Q

Desiccation

A
  • Condition where microorganisms cannot grow/reproduce in the absence of water
  • When water is available again, they can resume their growth
  • Bacteriostatic (will not kill, only inhibits)
  • Lyophylization
27
Q

Lyophilization

A

(freeze-drying), used for long-term preservation of microbial cultures

28
Q

Filtration

A
  • Removal of microorganisms by passage through pores
  • Pores need to be small enough to hold back microbes
  • Purpose of wearing face masks during surgery and for HEPA filters
29
Q

Osmotic Pressure

A
  • High concentration of salt and sugar in food to inhibit growth
  • Microbial cells in hypertonic solution lose water and cannot grow/multiply
30
Q

Radiation: two types

A

Ionizing radiation
Nonionizing radiation

31
Q

Ionizing radiation

A
  • Ejects electrons
  • Creates hydroxyl radicals
  • Good for controlling growth on gloves, syringes, meat/food
32
Q

Nonionizing radiation

A
  • Excites electrons
  • UV light damages the DNA
  • Good for surface objects
33
Q

The mechanism of action for both types of radiation is the

A

damage to DNA

34
Q

Chemical Methods of Microbial control and types

A
  1. Phenolics
  2. Halogens
  3. Alcohols
  4. Heavy Metals
  5. Surfactants
  6. Oxidizing Agents
35
Q

Phenolics

A
  • Denatures proteins and disrupts the cell membranes
  • Triclosan: phenol and phenolics
  • Found in garbage and diapers
36
Q

Halogens

A
  • Damages proteins with denaturation
  • Iodine (oldest/most effective antispetic)
  • Chlorine (disinfects water, present in bleach)
  • Flouride (toothpaste)
  • Bromine (hot tubs)
37
Q

Alcohols

A
  • Kill bacteria and fungi but not endospores
  • Denatures proteins and disrupts plasma membrane
38
Q

Heavy Metals

A
  • Denatures proteins
  • Exs: Zinc, Mercury, Copper, Silver
39
Q

____ is often found in ___ creams

A

Silver is often found in burn creams

40
Q

Surfactants-3 types

A

Soap
Acid-anionic detergents
Cationic detergents

41
Q

Surfactants-mechanism of action

A

Disrupts cell membrane

42
Q

Soap

A
  • Good degerming agents
  • Doesn’t really kill/inhibit growth
43
Q

Acid-anionic detergents

A
  • Carries negative charge
  • Nontoxic and non-corrosive to humans
  • Fast-acting
  • Found in laundry detergent
44
Q

Cationic detergents

A
  • Carries positive charge
  • Most widely used cationic detergents are Quats, which disrupt the cell membrane and is bacteriocidal except for endospores
45
Q

Other than endospores, what else can Quats not destroy and why?

A

Mycobacteria due to the waxy cell membrane

46
Q

Oxidizing Agents

A
  • Damages cellular components of microbe
  • Ex: Hydrogen peroxide
47
Q

Hydrogen peroxide

A
  • Not a good antiseptic for open wounds due to the enzyme catalase
  • Good disinfectant for nonliving objects

Microbiology (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions