MICRO BIO CHAPTER 6 QUIZ Flashcards
1
Q
The survival growth of any microorganism in a given environment depends on its metabolic characteristics.
A
Microbial Growth
2
Q
What are the requirements for microbial growth it can be divided into 2 main categories
A
Physical and Chemical
3
Q
What formation can Microbial growth lead to?
A
Colony and Biofilm
4
Q
It is the aggregation or collection of cells arising from one single parent cell
A
Colony
5
Q
Collection of microbes living in a complex community
A
Biofilm
6
Q
Cold-loving
A
Psychrophiles
7
Q
moderate temperature
A
Mesophiles
8
Q
Heat-loving
A
Thermophiles
9
Q
Lowest temp at which the species will grow?
A
Minimum growth temperature
10
Q
Temperature at which the species grow best?
A
Optimum growth temperature
11
Q
highest temperature at which growth is possible?
A
Maximum growth temperature
12
Q
It refers to the acidity or alkalinity of a solution?
A
pH
13
Q
Most bacterias grow best in?
A
narrow pH range near neutrality
between pH 6.5 and 7.5
14
Q
what does pH mean?
A
Power of Hydrogen
15
Q
common ( most bacteria that thrive inside the body)
A
Neutrophiles
16
Q
Love acidic pH; example Helicobacter pylori (causative agent for peptic ulcer?
A
Acidophiles
17
Q
alkali loving bacteria; example vibrio cholarae (strives in small intestine)
A
Alkalinophiles
18
Q
is the force caused by a solution passing through a semi-permeable surface by osmosis, which is equal to the force required to resist the solution from passing back through the surface
A
Osmotic pressure
19
Q
Microorganisms obtain almost all their nutrients in solution from the surrounding water.
A
Osmotic Pressure
20
Q
A hypertonic environment will cause an osmotic loss of water causing plasmolysis?
A
osmotic pressure
21
Q
shrinkage of cell’s cytoplasm
A
plasmolysis
22
Q
salt loving
A
Halophiles
23
Q
microorganisms that require high salt concentration for growth?
A
Extreme halophiles
24
Q
aka. Obligate halophiles
A
Extreme Halophiles
25
Microorganisms which do not require high salt concentration but are to grow at salt concentrations 2%
Facultative Halophiles
26
is the structural backbone of living matter?
Carbon
27
needed for all the organic compounds that make up a living cell (ex. Source of energy)
Carbon
28
carbon source is from an organic molecule
Chemoheterotrophs
29
carbon source is from the carbon dioxide
Autotrophs
30
It is a chemical that is primarily used to form the amino group of the amino acids of proteins?
Nitrogen
31
It is used to synthesize sulfur containing amino acids and vitamins.
Sulfur
32
is essential for synthesis of nucleic acids and phospholipids of cell membranes as well as energy bods of ATP
Phosphorous
33
Elements present in living tissues in very low amounts
Trace Elements
34
What are the examples of trace elements?
Iron, copper, molybdenum and zinc
35
Most are essential for function of certain enzymes, usually as cofactors
Trace Elements
36
Bacteria can be classified based on how the require?
Oxygen
37
This are organisms that require oxygen
Obligate aerobes
38
Have enzymes such as Catalase and Superoxide Dismutase that allows the toxic form of oxygen to be neutralized?
Obligate Aerobes
39
In Obligate aerobes where do growth occur?
where high concentrations of oxygen have diffuses into the medium
40
Both aerobic and anaerobic growth; greater growth in presence of oxygen
Facultative Anaerobes
41
Only anaerobic growth;
growth ceases in presence of
oxygen
Obligate anaerobes
42
Growth occurs only when
there is no oxygen
Obligate Anaerobes
43
Lacks
enzymes to
neutralize harmful
forms of oxygen;
cannot tolerate
oxygen
Obligate Anaerobes
44
Only anaerobic growth; but
growth continues in presence
of oxygen
Aerotolerant Anaerobes
45
Growth occurs evenly; oxygen
has no effect
Aerotolerant Anaerobes
46
Presence of one
enzyme, SOD, allows
harmful forms of oxygen
to be partially
neutralized; tolerates
oxygen.
Aerotolerant Anaerobes
47
Only aerobic growth; oxygen
required in low concentration
Microaerophiles
48
Growth occurs only where a
low concentration of oxygen
has diffused into medium
Microaerophiles
49
Produce lethal
amounts of toxic
forms of oxygen if
exposed to normal
atmospheric oxygen.
Microaerophiles
50
A nutrient material
prepared for the growth of
microorganisms in a laboratory.
Culture media
51
Microbes that grow and
multiply in or on a culture
medium.
Culture
52
How can a pure culture that contains only one specie or strain be obtained?
Streak Plate Method
53
the one with the exact chemical
composition.
Chemically-Defined Media
54
Usually reserved for
laboratory experimental work
for the growth of autotrophic
media
Chemically Defined Media
55
exact chemical
composition varies from batch to
batch and is also used in laboratories
Complex Media
56
Suspension of
microorganisms
Inoculum
57
Introduction of
microbes into culture medium
Inoculation
58
Visible growth of microbes
on the surface of the
medium
Colony
59
What is CFU?
Colony-Forming Unit
60
For organisms with no
special requirements (non-fastidious
organisms)
SIMPLE MEDIA
61
(Nutrient Broth)
Mueller hinton broth
Liquid Broth
62
(Nutrient Agar)
-Mueller hinton agar
Solid Media
63
For organisms
with special contents/ nutrients required
for their growth (fastidious organisms)
Enriched Media
64
for high protein-diet
organisms
Milk Agar
65
for high protein-diet
organisms
Chocolate Agar
66
- for organisms
that need hemoglobin for survival.
Blood Agar plate
67
used to
distinguish one group of organisms from
another
Differential Media
68
→ Contains 5% sheep’s blood
→ Differential by identifying the type
of hemolysis
→ Some bacteria secrete enzymes
that lyse RBCs such that a clearing
around the colony appears.
Blood Agar Plate
69
partial
hemolysis (red green)
Alpha hemolytic
70
complete
hemolysis (red clear)
Beta hemolytic
71
no hemolysis
(red red)
Gamma-hemolytic
72
example of gamma hemolytic
enterococci
73
example of beta hemolytic
S. pyogenes (cause of scarlet fever)
S. agalactiae ( neonate pneumonia)
74
for G(-) bacteria
Lactose
MacConkey Agar
75
- fermenting G(-) bacteriaPINK
Lactose
76
Example of lactose
Neisseria spp.
77
fermenting G(-)
bacteria
Non-lactose
78
examples of non lactose
Pseudomonas, salmonella, shigella and proteus
79
only allow certain
strain of organisms to grow in the
medium.
Selective Media
80
Contains blood, potato extract,
glycerol, and antibiotic
(Cephalexin or Penicilin) or
Nicotinamide for the isolation of
Bordetella pertussis
Bordet-Gengou Agar
81
Other name of Bordetella pertussis
Whooping cough/Perussis
82
→ Complex mixture of different
amino acids, vitamins and growth
factors, enriched with bovine and
rabbit serum, with peptone (as
nitrogen source) and glucose (as
energy source) for the isolation of
Borrelia burgdorferi
Barbour-Stoenner-Kelly (BSK) Agar
83
Other name of Borella burgdoferi
Lyme disease
84
→ Complex mixture generally
contains potato starch with
glycerated egg-based medium
used for cultivation and isolation
of Mycobacterium species.
Lowenstein-Jensen (LJ) Media
85
Examples of Lowenstein-Jensen (LJ) Media
M. tubercolosis, M. leprae
(Hansen's disease/ Leprosy)
86
Types of preserving Bacterial Cultures
Deep freezing (low temperatures)
Lyophilization (freeze drying)
87
It is the asexual
reproduction (cell division) of a
bacterium into two new daughter cells, in
a process called binary fission.
Bacterial Growth
88
It is the most common
form of reproduction of prokaryotes
(bacteria) in which a fully grown parent
cell splits into 2 halves, producing 2 new
daughter cells
Binary fission
89
a time required
for a cell to divide or for a
population to double.
Generation time
90
Intense activity
preparing for population growth
but no increase in population
Lag Phase
91
Logarithmic, or
exponential, increase in
population (prone to the effects of penicillin)
Log Phase
92
(fixed; equal
death and equal new cells): Period
of equilibrium; microbial deaths
balance production of new cells.
Stationary Phase
93
Population is
decreasing at a logarithmic rate
*the logarithmic growth in the log
phase is due to reproduction by
binary fission (bacteria) or mitosis
(yeast).
Death Phase
94
→ Reflects the number of viable
microbes and assumes that each
bacterium grows into a single
colony.
Done by: Pour Plate or Spread
Plate Method
Heterotrophic Plate Count (Direct
Method)
95
Bacteria that are retained on
the surface of the membrane filter
and then the membrane filter is
transferred to a medium for it to
grow and subsequently counted.
Filtration
96
Can be used for microbes that will
grow in a liquid medium and is
only a statistical estimation
Most Probable Number Method
97
If no
bacteria, the solution should be
clear. The more turbid (more
blurry), more bacteria is present
Turbidity Measurement Using a
Spectrophotometer
98
More metabolic activity,
the greater number of bacteria is
present.
Measurement of Metabolic
Activity
99
For yeast and fungal
growth
Dry Weight
100
Destruction or
removal of ALL FORMS OF
MICROBIAL LIFE, including
endospore but with the possible
exception of prions.
Sterilization
101
Sufficient heat treatment to kill
endospores of Clostridium
botulinum in canned food.
Commercial Sterilization
102
Destruction of
vegetative pathogens on
inanimate objects.
Disinfection
103
Destruction of
vegetative pathogens on living
tissue.
Antisepsis
104
Removal of microbes
from a limited area, such as the
skin around an injection site.
Degerming
105
Treatment is
intended to lower microbial
counts on eating and drinking utensils to safe public health
levels
Sanitization
106
is the process
by which we greatly reduce the
number of microorganisms
present
Decontamination
107
MOA: Kills microorganisms by
coagulating (denaturing) of
proteins
(a) Boiling
(b) Autoclave (15 psi, 121
degrees Celsius for 15-30
minutes) kills all microorganisms
except prions (misfolded proteins)
Moist Heat Sterilization
108
Employs mild heating which is
sufficient to microorganisms that
can cause particular spoilage
problem without damaging the
taste of the product.
Pasterization
109
Phosphatase test (+ yellow)
Pasterization
110
Alkaline phosphatase : a normal
enzyme present in milk, but is
denatured during?
Pasteurization
111
Standard: at least 72 degrees
Celsius for only 15 seconds (High temperature short-time (HTST)
Pasteurization
112
Ultra-high-temperature (UHT)
treatment
Sterilization
113
All microorganisms present are
killed
Sterilization
114
Sterilized dairy milk can be stored
without refrigeration
Sterilization
115
MOA: Oxidation
(a) Direct flaming
(b) Hot-air sterilization
Dry Heat Sterilization
116
- Items to be sterilized are placed
in an oven maintained with
temperature of about 170
degrees Celsius for nearly 2
hours. (more time and higher
temp needed because there is no
water present)
Dry Heat Sterilization
117
Longer period and higher
temperature are required because
heat in water is more readily
transferred to a cool body than
heat in air.
Dry Heat Sterilization
118
It is the passage of a liquid or gas
through a screenlike material with
pores small enough to retain
microorganisms
Filtration
119
Remove almost all
microorganisms larger than
about 0.3 micrometer in
diameter.
High-efficiency particulate air
(HEPA) filters
120
It alters the molecular structures
of proteins and carbohydrates
resulting in the rapid inactivation
of vegetative bacterial cells.
HIGH PRESSURE
121
Advantage: Preservation of
flavors, colors and nutrient values
of the products.
HIGH PRESSURE
122
Process of extreme drying
(absence of water)
Dessication
123
Involves ordinary refrigeration
(O-7 degrees celsius) which
can promote bacteriostatic
effect
Lyophilization/ freeze-drying
124
Which is much more capable than growing bacteria in material with moisture or high osmotic pressures?
Molds and Yeasts
125
Creates hypertonic environment
that causes water to leave the
microbial cell
OSMOTIC PRESSURE
126
Can be used for sterilization of
medical supplies (petri dish,
plastic syringes) or food (spices,
meat)
RADIATION
127
MOA: ionization of water which
forms highly reactive hydroxyl
radicals, that kill organisms by
reacting with organic cellular
components (DNA) and damaging
them.
RADIATION
128
Short wavelength, high energy
RADIATION
129
UV Light (germicidal action at
260 nm_
Nonionizing radiation
130
MOA: Damages the DNA of
exposed cells by causing bonds to
form between adjacent pyrimidine
bases (usually thymines), in DNA
chains, which will then inhibit
correct replication of DNA.
Nonionizing radiation
131
Commonly used in air sterilization
(hospital rooms, operating rooms,
cafeteria)
Nonionizing radiation
132
what are examples of nonionizing radiation?
Microwaves
133
First
used by Lister to control surgical
infections in the operating room.
PHENOL(CARBOLI ACID)
134
Now rarely used as an
antiseptic or disinfectant
because it irritates the skin
and has a disagreeable odor
Phenol
135
Contain molecule
of phenol that has been
chemically altered to reduce its
irritating qualities or increase its
antibacterial activity.
Phenolics (Phenol Derivatives)
136
Derivatives of phenol that contain
2 phenolic groups connected by a
bridge.
Bisphenols
137
- antibacterial soaps,
toothpastes and mouthwashes
- It inhibits enzymes
needed for the biosynthesis of
fatty acids (lipids-affects the
integrity if plasma membrane)
Triclosan
138
Have a broad spectrum of activity
Biguanides
139
best-known
biguanide; frequently used for
microbial control on skin and
mucous membrane; Listerine,
gynepro feminine wash
Chlorhexidine
140
Iodine and chlorine derivatives
Halogens
141
is the oldest and most
effective antiseptics.
iodine
142
effective against all kinds of
bacteria, various fungi and some
viruses
iodine
143
Most common commercial
preparation of iodine
Povidone-iodine (Betadine)
144
A surface-active iodophor that
improves the wetting action and
serves as a reservoir of free
iodine
Povidone-iodine (Betadine)
145
MOA: due to hypochlorous acid
(HOCl) formed when chlorine is
added to water
Chlorine
146
other term of chlorine?
germicidal
147
most effective form of chlorine
because of its neutral charge and
diffuses rapidly through the cell
wall.
Hypochlorous acid
148
- a strong oxidizing agent that
prevents cellular enzyme system
from functioning
Hypochlorite
149
Used to disinfect dairy
equipment and restaurant eating
utensils
Calcium hypochlorite
150
used to household disinfectant
and bleach (Clorox)
- used in municipal chlorination of
drinking water.
Sodium hypochlorite
151
- Effectively kills bacteria and fungi but
not endospores and nonenveloped
viruses
Alcohol
152
what are the two most commonly used alcohol?
Ethanol and isopropanol
153
MOA: Oligodynamic action
-ability of very small amounts of heavy
metals to exert antimicrobial activity
Heavy Metals
154
used as an antiseptic in a 1% AgNO3
solution against eye infection in
newborns (opthalmia neonatorum)
Silver
155
- available as topical cream for use on
burns; burn patients are most
susceptible to pseudomonal infections
so burns are wrapped with
silversulfadiazine
Silversulfadiazine (Flammazine)
156
once used as a disinfectant with very
broad spectrum of activity primarily as a
bacteriostatic
Mercuric chloride
157
used as additives to control fungal
diseases of plants
Copper 8-hydroxyquinoline
158
common ingredient in mouthwashes
Zinc chloride
159
antimicrobial ingredient in antidandruff
shampoos
Zinc pyrithione
160
decrease surface tension among
molecules of a liquid
- may be anionic, cationic, nonionic
Surface-Active Agents (Surfactants)
161
has little value as an antiseptic,
but it does have an important function in
the mechanical removal of microbes
through scrubbing
Soaps and detergents
162
MOA of soap and detergents
Emulsification
163
They are very important in cleaning
food-processing facilities (dairy utensils
and equipment)
Acid-Anionic Sanitizers
164
Usually in combinations of phosphoric
acid with a surface-active agent.
Acid-Anionic Sanitizers
165
AKA: cationic detergents (positively
charged)
Quaternary Ammonium Compounds (Quats)
166
They are also fungicidal, amebicidal,
and virucidal against enveloped viruses
Quaternary Ammonium Compounds (Quats)
167
These are chemical preservatives
frequently added to foods to retard
spoilage.
Chemical Food Preservatives
168
Once used as disinfectant especially in
winemaking
Sulfur dioxide
169
Prevent molds from growing in acidic
foods (cheese and soft drinks)
Sorbic acid, potassium sorbate and
Na benzoate
170
added to meat products (ham, bacon,
hotdogs and sausages)
Na nitrate and Na nitrite
171
what are the function of Na nitrite?
Preserve red color of meat
Prevent growth of botulism edospores
172
Na nitrate and Na nitrite
Aldehydes
173
It is used extensively to preserve biological specimens and
inactivate bacteria and viruses in
vaccines
Formaldehyde and formalin
174
less irritating and more effective than
formaldehyde.
Glutaraldehyde (2% Cidex)
175
used for materials that are temperature
sensitive (materials that can’t be used in
autoclaves for sterilization)
Glutaraldehyde (2% Cidex)
176
Advantages: Sterilization is possible
in ambient temperatures and is highly
penetrating.
Ethylene oxide
177
It was used to fumigate enclosed
buildings contaminated with endospores
of anthrax.
Chlorine dioxide
178
Its most common use is in water
treatment prior to chlorination.
Chlorine dioxide
179
