Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Micro Para Lec > Midterm_Microbial Growth Control > Flashcards

Midterm_Microbial Growth Control Flashcards

1
Q

Methods for Microbial Control

A
  • Physical Agents
  • Chemical Agents
  • Mechanical Removal Methods
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Physical Agents for Microbe growth control

A

Heat and Radiation

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

Physical Agents: Heat

A

Dry
- Incineration for sterilization
- Dry oven for sterilization

Moist
- Steam under pressure for sterilization
- Boiling water, hot water, pasteurization for disinfection

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

Physical Agents Radiation

A

Ionizing
- X-ray, cathode, gamma for sterilization

Nonionizing
- UV for disinfection

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

Chemical Agents for Microbe Growth Control

A

Gases and Liquids

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

Chemical Agents: Gas

A

Sterilization and Disinfection

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

Chemical Agents: Liquids

A

Animate
- chemotherapy
- antisepsis

Inanimate
- Disinfection
- Sterilization

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

Mechanical Removal Methods

A

Filtration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Mechanical Removal Methods: Filtration

A

Air for disinfection

Liquids for Sterilization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
  • its the destruction or removal of vegetative pathogens but not bacterial endospores
  • used only on inanimate objects
A

Disinfection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
  • Complete removal or destruction of all viable microorganisms
  • used on inanimate objects
A

Sterilization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Chemicals applied to body surfaces to destroy or inhibit vegetative pathogens

A

Antiseptics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Chemicals used internally to kill or inhibit the growth of microorganisms within host tissues

A

Chemotherapy

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

General Principles and Growth Control by Heat
- The killing or removal of all viable organisms within a growth medium

A

Sterilization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

General Principles and Growth Control by Heat
- Effectively limiting microbial growth

A

Inhibition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

General Principles and Growth Control by Heat
- The treatment of an object to make it safe to handle

A

Decontamination

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

General Principles and Growth Control by Heat
- Directly targets the removal of all pathogens, not necessarily all microorganisms

A

Disinfection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

General Principles and Growth Control by Heat
- most widely used method of controlling microbial growth

A

Heat sterilization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

General Principles and Growth Control by Heat
- bacteria produce resistant cells that Can survive heat that would rapidly kill vegetative cells

A

endospores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

High temperatures ___________ macromolecules

A

denature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Amount of time required to reduce viability tenfold

A

decimal reduction time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q
  • sealed device that uses steam under pressure
  • Allows temperature of water to get above 100ºC
  • uses high temperature to kills the microbes
A

autoclave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Physical Control Methods

A
  • Pasteurization
  • Radiation
  • Filtration
24
Q

Physical Control Methods
- process of using precisely controlled heat to reduce the microbial load in heat-sensitive liquids
- Does not kill all organisms

A

Pasteurization

25
can reduce microbial growth
Microwaves, UV, X-rays, gamma rays, and electrons
26
Physical Control Methods - Electromagnetic radiation that produces ions and other reactive molecules - Generates electrons, hydroxyl radicals, and hydride radicals
Ionizing radiation
27
- has sufficient energy to cause modifications and breaks in DNA - useful for decontaminating surfaces - Cannot penetrate solid, opaque, or light-absorbing surfaces
UV
28
Physical Control Methods used for sterilization in the medical field and food industry
Radiation
29
Sources of radiation
cathode ray tubes, X-rays, and radioactive nuclides
30
Physical Control Methods - avoids the use of heat on sensitive liquids and gases - has Pores of filter are too small for organisms to pass through but allow only liquid or gas to pass through
Filtration
31
Examples of filters
Depth filters (HEPA filters) and Membrane filters (Function more like a sieve)
32
A type of membrane filter
nucleation track (nucleopore) filter
33
Filtration can be accomplished by syringe, pump, or vacuum
Membrane filters
34
3 Classifications of Antimicrobial Agents
1. bacteriostatic 2. bacteriocidal 3. bacteriolytic
35
Chemical Methods
- Phenol - Phenolics - Alchohols - Halogens - Oxidizing agents - Surfactants - Heavy Metals - Aldehydes - Gaseous agents - Antimicrobials
36
why 70% ethanol is more effective than 100% ethanol for sterilization
- to prevent skin breakdown - prevent quick evaporation of alcohol before killing the microbe intended
37
smallest amount of an agent needed to inhibit growth of a microorganism - Varies with the organism used, inoculum size, temperature
Minimum inhibitory concentration (MIC)
38
- uses solid media - Antimicrobial agent added to filter paper disc - MIC is reached at some distance
Disc diffusion assay
39
Area of no growth around disc during Disc diffusion assay
Zone of inhibition
40
antimicrobial agents can be divided into two categories
1. Products used to control microorganisms in commercial and industrial applications - chemicals in foods, air conditioning cooling towers, textile and paper products, fuel tanks 2. Products designed to prevent growth of human pathogens in inanimate environments and on external body surfaces - Sterilants, disinfectants, sanitizers, and antiseptics
41
Conditions Influencing the Effectiveness of Antimicrobial Agent Activity
- Population size - Population composition - Concentration or intensity of an antimicrobial agent - Duration of exposure - Temperature - Local environment
42
Conditions Influencing the Effectiveness of Antimicrobial Agent Activity - larger populations take longer to kill than smaller populations
Population size
43
Conditions Influencing the Effectiveness of Antimicrobial Agent Activity - microorganisms differ markedly in their sensitivity to antimicrobial agents
Population composition
44
Conditions Influencing the Effectiveness of Antimicrobial Agent Activity - usually higher concentrations or intensities kill more rapidly - relationship is not linear
Concentration or intensity of an antimicrobial agent
45
Conditions Influencing the Effectiveness of Antimicrobial Agent Activity - longer exposure = more organisms killed
Duration of exposure
46
Conditions Influencing the Effectiveness of Antimicrobial Agent Activity - higher temperatures usually increase amount of killing
Temperature
47
Conditions Influencing the Effectiveness of Antimicrobial Agent Activity - many factors (e.g., pH, viscosity and concentration of organic matter) can profoundly impact effectiveness - organisms in biofilms are physiologically altered and less susceptible to many antimicrobial agents
Local environment
48
- closed-system microbial culture of fixed volume
Batch culture
49
Growth Cycle Note: Typical growth curve for population of cells grown in a closed system is characterized by four phases
1. Lag Phase 2. Exponential Phase 3. Stationary Phase 4. Death Phase
50
Growth Cycle, Identify the phase - Interval between inoculation of a culture and beginning of growth
Lag phase
51
Growth Cycle, Identify the phase - Cells in this phase are typically in the healthiest state
Exponential phase
52
Growth Cycle, Identify the phase - Growth rate of population is zero - Either an essential nutrient is used up, or waste product of the organism accumulates in the medium
Stationary phase
53
Growth Cycle, Identify the phase - If incubation continues after cells reach stationary phase, the cells will eventually die
Death phase
54
an open-system microbial culture of fixed volume
Continuous culture
55
- most common type of continuous culture device - Both growth rate and population density of culture can be controlled independently and simultaneously
Chemostat
56
rate at which fresh medium is pumped in and spent medium is pumped out
Dilution rate

Micro Para Lec (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions