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Microbio > Lecture 2 > Flashcards

Lecture 2 Flashcards

1
Q

Bacterial communities that secrete polysaccharides and other hydrophilic polymers. The mesh-like accumulation helps protect the bacteria from antibiotics and disinfectants. This slippery, grimy surface is called?

A

Bioflim

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2
Q

A population descended from a single cell and therefore contains only one species

A

A Pure Culture

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3
Q

A polysaccharide extracted from seaweed used to solidify culture media

A

Agar

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4
Q

Qualities of a petri dish

A

It excludes airborne contaminants but is not airtight
two-part covered container made of plastic or glass
Culture medium in Petri dish is referred to as a plate of that medium

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5
Q

The method of using a sterile loop to spread a small culture sample over a medium in a pattern that gradually thins out the sample, resulting in isolated colonies

A

Streak plate method

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6
Q

Qualities of Batch culture

A
  1. Nutrients are not renewed
  2. Wasters are not removed
  3. Typically involves growth of bacteria or Archean either on agar plates or in tubes of broth
  4. It is a closed system
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7
Q

A distinct mass of microorganisms which develop from a single cell growing on a solid medium

A

Colony

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8
Q

Order of normal bacterial growth curve

A
  1. Lag phase
  2. Exponential or log phase
  3. Stationary phase
  4. Death phase
  5. Prolonged decline phase
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9
Q

the initial phase after bacterial cells are placed into a new environment and are gearing up for cell division, but their numbers have not yet increased

A

Lag Phase

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10
Q

During what phase of the growth curve is generation time measured?

A

Log/exponential phase

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11
Q

Phase of growth in which the number of new cells balance the number of declining cells

A

Stationary phase

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12
Q

Phase in which the number of viable cells is decreasing

A

Death phase

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13
Q

In what ways is microbial growth in a colony the same as growth in a liquid?

A

Both involve a lag phase followed by exponential growth
In both cases, cells compete with one another for available nutrients

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14
Q

Device used to keep cells in a state of constant growth

A

Chemostat

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15
Q

Term used to describe microorganisms that live in harsh environments that kill most other organisms

A

Extremophiles

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16
Q

Environmental factors that have the most impact on microbial growth

A

Atmosphere, pH, water availability, and temperature

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17
Q

Term for a microorganism that has an optimum temperature between -5 C and 15 C

A

Psychrophile

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18
Q

Term for a microorganism that has an optimal temp between 15 C and 30 C but grows best on refrigerated foods

A

Psychrotroph

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19
Q

E. coli and most other common bacteria are in what optimal temperature group?

A

Mesophiles

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20
Q

Thermophiles would most likely be found where?

A

Hot springs and compost heaps

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21
Q

Strictly aerobic organism, requires O2 for survival

A

Obligate aerobe

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22
Q

Human pathogens, adapted to growth in the body belong to which temperature group?

A

Mesophiles

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23
Q

Microorganisms that can grow without O2 but grow faster in the presence of O2

A

Facultative anaerobes

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24
Q

Microorganisms that cannot multiply if O2 is present, often killed by brief exposure to air

A

Obligate anaerobes (anaerobes)

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25
Q

Microorganisms that require small amounts of O2 for aerobic respiration. Large quantities of O2 inhibit their growth

A

Microaerophiles

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26
Q

Microorganisms that are indifferent to O2, can grow in its presence but do not use O2 to harvest energy

A

Aerotolerant Anaerobes (aka obligate fermenters cus fermentation is their only metabolic option)

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27
Q

Microorganisms that are indifferent to O2, can grow in its presence but do not use O2 to harvest energy

A

Aerotolerant Anaerobes (aka obligate fermenters cus fermentation is their only metabolic option)

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28
Q

An aerobe that could be found on the surface of the skin, in the large intestine, or a deep wound

A

Facultative anaerobe

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29
Q

Water diffuses out of a cell due to osmosis. This results in what?

A

Plasmolysis

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30
Q

organism that requires organic compounds for its carbon and energy needs

A

Heterotroph

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31
Q

Prokaryotes that grow in alkaline conditions bring what into the cell?

A

Protons to neutralize internal pH

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32
Q

Organisms that use CO2 as a carbon source

A

Autotrophs

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33
Q

Animals could not survive without autotrophs because without them the world would run out of ?

A

Organic carbon

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34
Q

An organism that must consume organic matter is called a?

A

Heterotroph

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35
Q

Some microorganisms convert nitrogen gas (N2) to ammonia in a process called?

A

Nitrogen fixation

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36
Q

If an oil spill occurred in the ocean, what might we add to speed up the rate of microbial growth?

A

Nitrogen and phosphorus because they are often limiting nutrients in the ocean

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37
Q

An organic compound that a microorganism cannot synthesize and therefore must be provided in the growth medium

A

A Growth Factor

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38
Q

Process of autotrophs converting inorganic carbon to organic carbon

A

Carbon fixation

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39
Q

An organism that gets its energy directly from sunlight

A

Phototroph

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40
Q

A media containing ingredients like extracts of animals, plants, or yeasts, meat extracts, and blood and serum

A

Complex media

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41
Q

A medium that contains an ingredient that inhibit is the growth of some bacteria while allowing others to grow

A

Selective medium

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42
Q

Organism that uses light for energy and carbon dioxide as a carbon source

A

Photoautotroph

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43
Q

Media that supports the growth of many microbes but contains substances that certain microbes change in recognizable way

A

Differential media

44
Q

How are liquid batch cultures most often aerated to support the growth of aerobic microbes?

A

They are grown in tubes or flasks that are continuously shaken

45
Q

Thayer-Martin agar is chocolate agar to which 3 or more antimicrobial drugs have been added. What type of medium is this?

A

Complex and selective

46
Q

Determines the number of total cells in a sample

A

Direct cell count

47
Q

Viable cell counts determine the number of?

A

Cells capable of multiplying

48
Q

A sample reduced in concentration through successive resuspension in the same volumes of diluent

A

Serial dilution

49
Q

Technique that uses a sterile tool, such as an L-shaped glass rod, to distribute a diluted sample evenly around the surface of a solid agar plate

A

The spread-plate technique

50
Q

Term that describes the appearance of a cloudy broth culture

A

Turbidity

51
Q

How many colony-forming units (CFUs) are presumed to result in a single colony using the viable plate method?

A

1

52
Q

A sterile object is free of?

A

All viable microorganisms and viruses

53
Q

The process of destroying or removing all microbes through physical or chemical processes is?

A

Sterilization

54
Q

Elimination of most or all pathogens on or in a material

A

Disinfection

55
Q

Antimicrobial chemical that is non-toxic enough to be used on skin

A

Antiseptic

56
Q

Chemical that kills harmful microbes

A

Germicide

57
Q

Chemical that kills bacteria

A

Bactericide

58
Q

Chemical that kills fungi

A

Fungicide

59
Q

Chemical that inactivates viruses

A

Virucide (notice “inactivate” because viruses are not living)

60
Q

The use of specific methods to prevent microbes from contaminating an environment is termed?

A

Aseptic technique

61
Q

Potentially harmful chemicals that form when chlorine and similar substances react with chemicals in the water

A

Disinfection by-products (DBPs)

62
Q

what 4 Microbial groups are the most resistant to Chemical control methods?

A

Protozoan cysts and oocysts, non-enveloped viruses, bacterial endospores, Mycobacterium species

63
Q

When selecting an appropriate chemical disinfectant, it is important to realize that the death rate is significantly influenced by _____ and _____

A

pH and temperature

64
Q

Prior to being used to grow cultures, media is ____ to ensure that the cultures remain pure

A

Sterilized

65
Q

What is the most highly resistant microbial structure?

A

Endospore

66
Q

3 categories of medical instruments according to their risk for transmitting disease

A

Critical, semi-critical, and non critical instruments

67
Q

Process that is an alternative to heat for sterilization and disinfection, but the process damages some types of plastics

A

Irradiation

68
Q

4 Physical ways to remove or destroy microbes

A
  1. Filtration
  2. Autoclaving
  3. Incineration
  4. Ultraviolet radiation
69
Q

A surgical scalpel is rated as a ____ instrument because it penetrates skin and mucous membranes and therefore must be sterile

A

Critical

70
Q

What methods of microbial control use moist heat to destroy microbes?

A

Pressurized steam (autoclave), boiling, and pasteurization

71
Q

Boiling water for at least ____ mins can be an effective means of killing vegetative cells and viruses

A

5 minutes

72
Q

The most highly resistant microbial structure is the bacterial _____

A

Endospore

73
Q

Goals of pasteurization

A

Destroy pathogens and reduce the number of microbes

74
Q

When boiling or pasteurizing a sample, microorganisms are destroyed because?

A

their proteins are irreversibly denatured

75
Q

Pasteurization protects against what pathogens in milks and juices?

A

Brucellosis, typhoid fever, and salmonellosis

76
Q

An instrument used to carry out sterilization at high temperature and pressure

A

Autoclave

77
Q

The destruction of microbes by subjecting them to extremes of dry heat, reducing them to ashes

A

Incineration

78
Q

Common parameters (settings) for an Autoclave

A

121C at 15psi for 15mins

79
Q

A retort is an industrial sized autoclave that ensure that ____ are destroyed

A

Endospores of Clostridium Botulinum

80
Q

Common dry heat sterilization method used in the microbiology laboratory

A

Flaming the inoculating loop

81
Q

Ionizing radiation causes indirect tissue damage by reacting with O2 to produce?

A

Reactive Oxygen Species (ROS)

82
Q

A form of electromagnetic radiation in wavelengths from 220-300nm that kills microbes via DNA damage

A

Ultraviolet light

83
Q

High pressure is thought to kill microbes by altering their?

A

Proteins and cell membranes

84
Q

What type of radiation has enough energy to remove electrons from atoms, thereby destroying DNA and damaging cytoplasmic membranes?

A
85
Q

What type of radiation has enough energy to remove electrons from atoms, thereby destroying DNA and damaging cytoplasmic membranes?

A
86
Q

What type of radiation has enough energy to remove electrons from atoms, thereby destroying DNA and damaging cytoplasmic membranes?

A
87
Q

What type of radiation has enough energy to remove electrons from atoms, thereby destroying DNA and damaging cytoplasmic membranes?

A

Ionizing

88
Q

What type of radiation has enough energy to remove electrons from atoms, thereby destroying DNA and damaging cytoplasmic membranes?

A

Ionizing

89
Q

_____ destroy all microbes including viruses and endospores

A

Sterilants

90
Q

Aqueous solutions of alcohol at a concentration of ____ are more effective than 100% alcohol

A

60-80%

91
Q

______ (HPP) is used to decrease the number of microbes in food while maintaining the color and flavor

A

High Pressure Processing

92
Q

______ (HPP) is used to decrease the number of microbes in food while maintaining the color and flavor

A

High Pressure Processing

93
Q

Alcohol-based solutions of certain antimicrobial chemicals like iodine are called?

A

Tinctures

94
Q

Chemical class that destroy microorganisms by forming chemical bonds that cross-link and inactivate proteins and nucleic acids?

A

Aldehydes

95
Q

Disinfectants that destroy all viruses and vegetative organisms but not endospores are referred to as ?

A

High-level disinfectants

96
Q

How do aqueous solutions of alcohol affect microbes?

A

By damaging lipid membranes and by denaturing proteins

97
Q

Formalin is 37% aqueous solution of _____ that is used as a potent chemical fixative and microbicide

A

Formaldehyde

98
Q

Chlorhexidine solutions are commonly used for?

A

Antisepsis of skin and skin wound care and mouthwashes

99
Q

Ethylene oxide is a gaseous agent used for?

A

Sterilizing heat or moisture-sensitive items

100
Q

Halogens are highly reactive ____ agents that _____

A

Oxidizing, cause damage to proteins

101
Q

Used to kill bacteria and inactive viruses in vaccines. It can also preserve biological specimens

A

Formaldehyde

102
Q

3 disadvantages of using chlorine to disinfect drinking water

A

At levels used, it does not kill cryptosporidium parvum oocysts and Giardia lamblia cysts ,
organic material disrupts its germicidal activity,
It reacts with some organic compounds to form potential carcinogens

103
Q

Extremely useful gaseous sterilizing agent that destroys all microbes and is often used to sterilize fabric, equipment, and implantable devices

A

Ethylene oxide

104
Q

Chlorine and Iodine are common disinfectants that belong to a class of chemicals called?

A

Halogens

105
Q

Metal compounds typically kill microbes by ?

A

Inactivating enzymes and other proteins

106
Q

Hydrogen peroxide is a more effective germicide on living tissue or inanimate objects?

A

Inanimate objects

Microbio (14 decks)

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