MICROBIAL GROWTH AND METABOLISM- MICROBIAL CONTROL Flashcards

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1
Q

defined as a process of increase in the number of cells, cell mass and cell activity

A

microbial growth

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2
Q

indicators of microbial growth

A
  • Increase in both population size and population mass
  • Increase in cell number
  • Increase in cell mass
  • Increase in Metabolic activity
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3
Q

most bacteria grow by

A

binary fission

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4
Q

The increase in mass is a consequence of

A

Anabolic process

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5
Q

main reactions of cell synthesis are

A

polymerization reactions

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6
Q

process of regeneration of same type of progeny by parent cell is called as

A

reproductions

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7
Q

In microorganisms’ reproduction takes place by

A

sexual, asexual as well by vegetative propagation

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8
Q

In case of bacteria, reproduction is defined as ____ of new cells from a parental cell by cell division.

A

regeneration

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9
Q

The bacterial cell reproduces or regenerate by four major processes

A

BINARY FISSION
BUDDING
FRAGMENTATION
SPORULATION

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10
Q

normal reproductive method of bacteria

A

binary fission

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11
Q

single cell divides into two identical cells

A

binary fission

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12
Q

process by which most prokaryotes replicate

A

Binary fission

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13
Q

generally involves the separation of a single cell into two more or less identical daughter cells, each containing, among other things, at least one copy of the parental DNA

A

Binary fission

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14
Q

Most bacteria reproduce by a relatively simple asexual process called

A

binary fission

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15
Q

The time interval required for a bacterial cell to divide or
for a population of bacterial cells to double is called

A

generation time

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16
Q

Generation times for bacterial species growing in nature

may be as short as __ or as long as __

A

15 minutes

several days

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17
Q

parental cell forms a tuber like outgrowth, which after detachment from a parental cell gives rise to new cell with similar phenotypic and genotypic characters

A

BUDDING

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18
Q

The bacteria reproduce by budding is

A

Rhodopseudomonas acidophila

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19
Q

The yeast reproduce by budding

A

S. cerevisea

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20
Q

a mode of asexual reproduction common in filamentous

microorganisms like fungi and filamentous bacteria

A

Fragmentation

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21
Q

a small fragment is detached or dissociated from parental filament by mechanical damage

A

reproduction by fragmentation

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22
Q

Reproduction by Fragmentation occurs in filamentous cell of a ___ and filamentous fungi like __

A

Nocardia species

Aspergillus spp

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23
Q

Cellular events in the cells of certain prokaryotes may change and lead to the formation of new cell types. This type of activity is called

A

differentiation

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24
Q

Fragmentation: In bacteria dormant or resting structures of four kinds can be produced:

A

Heat resistant endospores
Exospores
Cysts
Conidia

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25
Q

are formed asexually without union of nuclear material from two different types of cells

A

Heat resistant endospores

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26
Q

Kind of heat resistant dormant structures produced by
bacteria and Cyanobacteria which were liberated by mother cell before cell lysis and which giving new vegetative structure after germination

A

Exospores

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27
Q

are formed asexually without union of nuclear material from two different types of cells

A

Cysts

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28
Q

The dormant structure of the fungus like Actinomycetes is a heat labile asexual spore that is formed at the end of special surface (aerial) cells by a process of fragmentation

A

Conidia

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29
Q

a process of formation of endospore inside the vegetative cell in nutrient deficient or adverse conditions.

A

SPORULATION

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30
Q

In some bacteria no internal food reserve, which gain nutrients from exogenous sources for sporulation, such sporulation is called

A

exogenous sporulation

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31
Q

Cell is asymmetrically partitioned by doubled membrane wall called as

A

spore septum

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32
Q

Asymmetric cytoplasmic division- Largest one

A

mother cell

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33
Q

Asymmetric cytoplasmic division- smallest one

A

forespore

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34
Q

Septum does not have

A

peptidoglycan

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35
Q

Stage IV: Cortex synthesis- occurs in two sub stages

A
  • deposition of primordial cell wall on inner forespore membrane
  • deposition of specific thick layer of peptidoglycan outside the primordial cell wall
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36
Q

Dipicolinic acid to Calcium ratio in most of spores

A

1:1

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37
Q

In this stage spore become retractile

A

Stage VI : Maturation

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38
Q

Any process, physical or chemical, that will destroy or remove all viable microorganisms (bacteria, fungi, spores, and virus) from an object or from a
particular environment

A

Sterilization

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39
Q

Total inactivation of all forms of microbial life in terms of the organism’s ability to reproduce

A

Sterilization

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40
Q

Is any cleansing technique that mechanically removes microorganisms or reduce the level of contaminants or microbial population to a safe level as determined by public health standards

A

Sanitization

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41
Q

Growth of microorganisms or the presence of microbial toxins in the blood and other tissues

A

Sepsis

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42
Q

Any practice that prevents the entry of infectious agents into sterile tissues thus preventing infection

A

Asepsis

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43
Q

Are used to prevent contamination of surgical instruments, medical personnel, and the patient during surgery and also in the food industry

A

Aseptic techniques

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44
Q

Are products/chemical agents used for the asepsis of living tissues applied directly to exposed body surfaces (skin, wounds, mucosa) and surgical incision to destroy or inhibit vegetative pathogens

A

Antiseptics

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45
Q

Applied topically to living tissues

A

Antiseptics

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46
Q

Refers to the use of physical process or chemical agent (disinfectants) that promotes killing, inhibition, or removal of microorganisms (vegetative or growing form) but not the resistant spores of bacteria

A

Disinfection

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47
Q

Is an agent used to reduce the viability of a microbial population below a threshold level that causes infection

A

Disinfectant

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48
Q

Are used on surfaces of inanimate objects (floors, tables)

A

Disinfectant

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49
Q

▪ meaning to kill
▪ Added when a killing action is implied
▪ a suffix indicating that the antimicrobial agent will kill or destroy a certain group of microorganism

A

Suffix “cide/cidal”

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50
Q

An agent that kills certain microorganisms

A

Germicide

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51
Q

An agent that kills bacteria. Most do not kill endospores

A

Bactericide

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52
Q

An agent that inactivates viruses

A

Viricide

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53
Q

An agent that kills fungi.

A

Fungicide

54
Q

An agent that kills bacterial endospores and of fungal spores

A

Sporicide

55
Q

▪ meaning to stand still / stop

▪ the agent will prevent the growth or multiplication of the type of organism but are not killed outright

A

Suffix “static/stasis”

56
Q

An agent that inhibits the growth of bacteria, but does not necessarily kill them

A

Bacteriostatic Agent

57
Q

prevents the growth of fungi

A

Fungistatic agent

58
Q

reference standard agent

A

Phenol

59
Q

official method used to test disinfectant potency

A

Phenol Coefficient Test

60
Q

designed to determine the ratio of the highest dilution of the germicide that will kill the test organism within a specified time to the greatest dilution of phenol showing the same result

A

Phenol Coefficient Test

61
Q

indicates disinfecting ability compared to that of phenol

A

Phenol Coefficient Test

62
Q
  • most reliable and universally applied method of sterilization
  • Whenever possible, should be the method of choice
A

HEAT

63
Q

2 kinds of heat

A

Dry & Moist

64
Q

Refers to minimum time required to kill all microbes at a specified temperature in a specified environment

A

Thermal Death Time

65
Q

: lowest temperature required to kill all microbes when time is held constant

A

Thermal Death Point

66
Q

Sterilization that requires higher temperature and longer period of heating

A

DRY HEAT

67
Q

denotes air with a low moisture content that has been heated by flame or electric heating coil

A

DRY HEAT

68
Q

DRY HEAT: Temp. ranges from

A

160°C – several thousand °C

69
Q

the ultimate sterilization

A

Incineration

70
Q

most widely used type of dry heat

A

Hot air oven

71
Q

Hot air oven: oven heat set

A

180 C for 2 hours

72
Q

more effective than dry heat, and kills bacteria faster

A

MOIST HEAT

73
Q

MOIST HEAT: temp ranges from

A

60-135°C

74
Q

Temp and time- Mesophilic non-sporeformers

A

60°C for 30min

75
Q

Temp and time- S. aureus / S. faecalis

A

60°C for 60mins

76
Q

Temp and time- Vegetative form of all bacteria, yeast & fungi

A

80°C for 5-10mins

77
Q

Temp and time- Sporeformers (C. botulinum)

A

120°C for 4mins

78
Q

can be relied only for disinfection and not for sterilization

A

Boiling

79
Q

is steam under pressure, obtained by heating water in a boiler

A

Live Steam

80
Q

Tyndallization also called

A

Fractional / Intermittent sterilization

81
Q

▪ it is used to sterilize heat-sensitive culture media containing materials such as carbohydrates, egg or serum
▪ kills both sporeformer & non-sporeformers

A

Tyndallization

82
Q

not a reliable method of sterilization

A

FREEZING

83
Q

the formation of ice crystals outside the cell causes the withdrawal of water from the cell interior, resulting in an increased intracellular electrolyte concentration and denaturation of proteins

A

FREEZING

84
Q

Primarily used in the preservation of bacterial cultures

A

FREEZING

85
Q

Reduces metabolic rate of most microbes so they cannot reproduce or produce toxins

A

Bacteriostatic effect

86
Q

defined as energy emitted from atomic activities and dispensed at high velocity through matter or space

A

RADIATION

87
Q

process of separating microorganism from contaminated solution

A

FILTRATION

88
Q

an effective method to remove microbes from air and liquids

A

FILTRATION

89
Q

used to prepare liquids that cannot withstand heat, including serum and other blood products, vaccines, drugs, IV fluids, enzymes and culture media

A

FILTRATION

90
Q

useful for trapping microorganism only

A

FILTRATION

91
Q

JUST READ

A
types of membrane filters: 
• Seitz – asbestos – cellulose 
• Sintered glass – glass filaments 
• Chamberland – unglazed porcelain 
• Berkefeld – diatomaceous earth
92
Q

• Composed of a mat of randomly arranged fibers composed of fiberglass
between 0.5 - 2.0 µm in diameter
• Used to provide a flow of sterile air to hospital /sterile rooms
• Critical in the prevention of the spread of airborne bacterial and viral organisms
• Medical-use hepa filtration systems also incorporate high-energy ultraviolet light units to kill off the live bacteria and viruses trapped by the filter media.

A

High Efficiency Particulate Air Filters (HEPA)

93
Q

Used to filter most bacteria. Don’t retain spirochetes, mycoplasmas and virus

A

0.22 and 0.45um Pores

94
Q

Retain all viruses and some large proteins

A

0.1m Pores

95
Q

SONIC VIBRATIONS uses

A

research laboratories and treating sewage H2O

96
Q

Factors affecting disinfectant potency

A
  1. Number of microorganisms
  2. Nature of microorganism
  3. Temperature
  4. pH
  5. Time
  6. Mode of action of the agents
  7. Concentration of the agent
97
Q
  • Substances that alter the energy relationship at interfaces producing a reduction of surface tension
  • disrupt the integrity of cell membrane
A

SURFACE ACTIVE AGENTS

98
Q
produce electrically (-) colloidal ions in the 
solution
A

Anionic agents

99
Q

produce electrically (+) ions in the solution

A

Cationic agents

100
Q

produce electrically neutral colloidal particles

in the solution; Not effective

A

Nonionic agents

101
Q

capable of acting either as anionic or cationic detergents

A

Ampholytic or amphoteric agents

102
Q

two cationic groups separated by a hydrophobic bridging structure

A

Biguanides

103
Q

at low concentration, these compounds are rapidly bactericidal causing leakage of cell contents and irreversible inactivation of membrane-bound oxidases and dehydrogenases

A

PHENOLIC COMPOUND

104
Q

Derived from coal tar are used to dissolve other chemicals, as disinfectants and deodorizers, and to make specific chemicals that kill insect pests

A

Cresols

105
Q

Minimizes concern over the spread of germs in public

facilities

A

LYSOL

106
Q

XYLENOLS known as

A

Dimethylphenols

107
Q

provide an insight into the interaction of organic solvents with
lipid membranes; dehydrate cells, disrupt membranes and cause
coagulation of protein

A

ALCOHOL

108
Q

penetrate the bacterial cell wall and denature the

proteins and enzymes inside of the cell

A

70% conc.

109
Q

coagulates the protein on the outside of the cell wall

and prevents any alcohol from entering the cell

A

95% conc.

110
Q

▪ Used as skin disinfectant because of their bactericidal action and ability to remove lipids from the skin surfaces
▪ Unable to kill spores; not relied for sterilization instruments

A

ETHYL ALCOHOL

111
Q

ETHYL ALCOHOL USES

A
  • to sterilize skin before cutaneous injections

- to disinfect thermometers

112
Q

Most effective type of alcohol

A

ISOPROPYL ALCOHOL

113
Q

used in the food and cosmetic industry to prevent growth of microorganisms

A

o Benzoic acid
o Lactic acid
o Acetic acid
o Propionic acid

114
Q

highly bactericidal for gonococci and routinely used as prophylaxis against opthalmia
neonatorum

A

Silver nitrate

115
Q

topical cream for burn patients

A

Silver sulfadiazine

116
Q

very toxic disinfectant, not used today

A

Mercuric chloride

117
Q

mercury- less toxic but unreliable as skin disinfectant

A

Metaphen, Merthiolate

and Mercurochrome

118
Q

is used to kill algae in pools and fish

tanks

A

Copper sulfate

119
Q
  • Kills fungi and their spores
  • Used for fungal infections like Tinea vesicolor infection,
    sebborheic dermatitis and dandruff
A

SELENIUM

120
Q

used in dandruff shampoos (Selsun blue)

A

Selinium sulfide

121
Q

is used in mouthwashes

A

Zinc chloride

122
Q

is used as antifungal agent in paints; widely used to treat a variety of other skin conditions, in products such as baby powder and barrier creams to treat diaper
rashes (Desitin) calamine cream, anti-dandruff shampoos, and antiseptic ointments

A

Zinc oxide

123
Q

are the most significant microbicidal halogens used in the clinic/hospitals and have been traditionally used for
both antiseptic and disinfectant purposes

A

Chlorine- and iodine-based compounds

124
Q

These are the new broad spectrum disinfectants that highly active against most microorganisms

A

Hydrogen peroxide

125
Q

the most widely used iodine

A

povidone-iodine (betadine)

126
Q

widely used as water disinfectant

A

Chlorine

127
Q

hypochlorites and elemental chlorine + H2O =

A

hypochlorous acid

128
Q

o widely used for sanitizing dairy products and food processing equipment
o employed as sanitizers in most households, hospitals, and public buildings
o Used as a bleaching agent

A

Hypochlorite solution

129
Q

Hypochlorite solution marketed as

A

Chlorox, Zonrox, Purex

130
Q

▪ broad-spectrum efficacy against viruses, bacteria,
yeasts, and bacterial & fungal spores
▪ clear, colorless liquid that is commercially available
in a variety of concentrations ranging from 3 to 90%

A

Hydrogen peroxide

131
Q

Often referred as Flavines because of their yellow color

A

Acridine dyes

132
Q

o used as “cold sterilant” for surgical instruments
o 10x more effective than formaldehyde as a bactericidal and sporocidal agent and less toxic
o Less irritating

A

Glutaraldehyde