Lab practical 2 Flashcards
1
Q
- molecule is oxidized to form CO2 and water
- ATP is generated as energy source through oxidative phosphorylation
A
Respiration
2
Q
- molecule partially break down to alcohols and aldehydes
- ATP is synthesized through substrate level phosphorylation
A
Fermentation
3
Q
pH indicator in MSA (fermentation testing)
A
phenol red
4
Q
In fermentative tests, if the phenol red is yellow it is ____ and indicates an ___
In fermentative tests, if the phenol red is red it is ____ and indicates an ___
A
positive / acid
negative / base (cannot perform fermentation)
5
Q
the fermentable carbohydrate included in the medium in fermentation tests
A
Glucose
6
Q
3 types of fermentation tests
A
- glucose
- lactose
- mannitol
7
Q
glucose, mannitol, and glucose test results
red = ____ and ___ pH
yellow = ____ and ___ pH
A
negative / basic
positive / acidic
8
Q
grow only in the absence of oxygen
A
strict anaerobes
9
Q
can grow either with or without oxygen
A
facultative anaerobes
10
Q
require oxygen to grow
A
aerobes
11
Q
- grow in oily regions of the skin
- degrade fatty secretions
A
diphtheroids
12
Q
- coagulase-negative, salt-tolerant
- grow well in dry areas
- produce antibacterial compounds to prevent other gram-positive bacteria from growth
A
staphylococci
13
Q
- causes facial skin flaking
- dermatophytes cause hair and skin infections (athletes foot)
- Malassezia furfur
A
fungi
14
Q
degradation of gelatin due to bacteria’s ability to degrade proteins that are responsible for solidity of gelatin
A
Liquefaction
15
Q
enzyme that breaks down proteins
A
Protease
16
Q
enzyme that breaks down gelatin
A
Gelatinase
17
Q
sum of biological reactions in an organism
A
metabolism
18
Q
Metabolic pathways that break down molecules, releasing energy.
AB = A+B
A
Catabolism
19
Q
Metabolic pathways that construct molecules, requiring energy.
A+B = AB
A
Anabolism
20
Q
protein molecule that catalyze various chemical reactions
A
enzymes
21
Q
indicator in glucose, mannitol, and glucose tests
A
phenol red
22
Q
Enzymes that function outside the bacterial cell walls to degrade the large molecule
A
exoenzymes
23
Q
example of exoenzymes
A
DNase, protease, and amylase
24
Q
- nitrate
- oxidase
- catalase
A
3 oxidation tests
25
Identifies bacteria that have cytochrome oxidase
Oxidase test
26
If it has the enzyme, the tube turns to ___ because it degrades protein/enzyme
liquid
27
positive oxidase test: __
negative oxidase test: __
purple; yellow
28
Electron transfer from cytochrome c to oxygen and produces oxidized cytochrome c and water
cytochrome oxidase
29
the enzyme breaks down harmful substances like H2O2 into water and oxygen
Catalse Test
30
- a by-product of aerobic bacterial respiration
- oxidizing reagent / harmful to enzymes, nucleic acids, and other molecules
hydrogen peroxide
31
positive catalase test results in ____
negative catalase test results in ____
bubbles; no bubbles
32
used to determine whether an organism reduces nitrate to nitrite
- determines if bacteria can use nitrate as a terminal electron acceptor
Nitrate Reduction Test
33
can use nitrate as a terminal electron acceptor
facultative anaerobic bacteria
34
Nitrate Reduction Strip Test
positive test = ____
negative test = ____
pink/red strip; no color change
(positive result means the presence of nitrite)
35
Nitrate Reduction Test
gas bubbles = use ___ ___
no gas bubbles = use ____
nitrogen gas; nitrate
36
Measures the production of mixed acids by fermentation of glucose
Methyl Red Test
37
the production of acids can ___ pH of methyl red medium below pH of 5
lower
38
indicator in mixed acid fermentation tests
methyl red
39
Methyl Red test results:
yellow = ____ with ____ pH
red = ___ with ____ pH
negative/basic ; positive/acidic
40
bacteria that are mixed acid fermentors produce ____ ___ which splits formic acid into CO2 and hydrogen gas
formic hydrogenlyase
41
detects the presence of acetoin, a precursor of 2,3 butanediol
Vogues-Proskauer (VP)
42
This reagent is used in the Voges-Proskauer test and turns pink in the presence of acetoin.
- detects 2,3 butanediol by converting chemical to acetoin
Barritt's reagent
43
Vogues-Proskauer (VP) results:
(have to shake tube after adding reagent)
positive result = ____
negative result = ____
pink; yellow
44
bacteria can use sodium citrate as the sole carbon source
Citrate Test
45
Citrate Test results:
positive result = ___ (color) and ___ pH
negative result = ___ (color) and ___ pH
dark blue/basic ; green/acidic
46
When citrate test is positive, ___ is released when turning from green to dark blue
ammonium
47
production of oxaloacetate and pyruvate through ___ cleavage
citrate
48
organisms that are positive for citrate us the enzymes ____ ____ to transport citrate into cell
citrate permease
49
ferment sugar to produce acid and gas
(glucose, lactose, mannitol)
sugar fermentation
50
pH indicator for sugar fermentation tests
phenyl red
51
Phenyl red turns medium ___ at __ pH
yellow; low
52
sugar fermentation results:
positive result = ___
negative result = ___
yellow & an acid; red & a base
53
sugar fermentation:
yellow medium = positive for ___
bubble = positive for ___
acid; gas
54
Differential Test; Detects the Production of Amylase (An exoenzyme that breaks down the sugar starch)
Starch Hydrolysis Test
55
The hydrolysis of the starch will create a ____ zone around the bacterial growth
clear
56
Starch hydrolysis results:
positive result: __
negative result: __
red/yellowish halo; clear
57
In order to interpret the results of the starch hydrolysis test, ____ must be added to the agar.
iodine
58
detects for the present of caseinase enzyme
Casein Hydrolysis Test
59
extracellular protease that degrades the protein casein
caseinase
60
slow digesting milk protein
casein
61
Casein Hydrolysis Test results
positive = ____
negative = ___
clear zone around bacteria ; no clear zone
62
used to detect the presence of lipase
Fat Hydrolysis Test
63
enzyme that breaks down fat
Lipase
64
Lipid Hydrolysis Test results
positive = ___
negative = ___
bacteria turns blue ; no color change
65
Media/reagent used = Tryptone broth/ Kovac's reagent End Product/ Enzyme = Tryptophanase // positive formation of red ring
Tryptophan Hydrolysis
66
used to detect the presence of tryptophanase
Tryptophan Hydrolysis Test
67
breaks down the amino acid tryptophan to indole, pyruvic acid, and ammonia
tryptophanase
68
use of ______ to breakdown tryptophan into indole and pyruvate
Kovac's reagent
69
by-product of tryptophan hydrolysis with pyruvate
indole
70
Tryptophan Hydrolysis Test results
positive =
negative =
has red ring ; no red ring
71
Indole ____ be broken down by bacteria
cannot
72
Used to differentiate organisms based on their ability to hydrolyze urea with the enzyme urease.
Urea Hydrolysis Test
73
Enzyme that changes urea into ammonia and carbon dioxide
Urease
74
Urea Hydrolysis Test results:
positive = ____ and ____ pH
negative = ____ and ____ pH
pink/basic ; yellow/acidic
75
urea --> ___ + __
CO2 + ammonia
76
used to determine glucose / lactose fermentation and H2S production from breakdown of cysteine
Kligers Iron Agar Test
77
In the Kligers Iron Agar Test:
positive color is ____ and ___ pH and the negative color is ____ and ____ pH
yellow/acidic ; red/basic
78
In the Kligers Iron Agar tube, the top sugar is ____ and the bottom sugar is ____
lactose/glucose
79
In the Kligers Iron Agar Test, if the bacteria produce gas the agar is ____
In the Kligers Iron Agar Test, H2S is produced the agar will turn _____
cracked; black
80
Kligers Iron Agar Test
81
DNA is sensitive to nonionizing radiation resulting in _____; ____ nm is the optimum absorption wavelength
pyrimidine dimers; 260 nm
82
-5C and 20C (arctic / Antarctic regions)
Psychrophiles
83
grows best between 20C and 40C ; the human pathogens are in this group (most bacteria)
Mesophiles
84
grow between 45C and 70 C ; soil bacteria
Thermophiles
85
grows above 75*C; Archaea thrive in very hot environments, such as volcanic springs.
Hypothermophiles
86
organisms that only grow near optimal temps
mesophiles
87
When bacteria is above optimal temp, the enzyme ____
When bacteria is below optimal temp, the enzyme ____
denatures; grows very slowly or not at all
88
When bacteria is above optimal temp, the cell membrane ____ in fluidity and can cause ____
When bacteria is below optimal temp, the cell membrane ____ in fluidity and ___ transport rates
increases / degeneration
decreases / lower
89
When bacteria is above or below optimal temp, ribosomes ____ function
cannot
90
S. marcescens produces _____ at optimal temperature
prodigiosin
91
The red pigment produced by S. marcescens
prodigiosin
92
temperature that S. marcescens produces prodigiosin
25 C
93
organisms used in the UV light experiment
B. cereus / S. aureus
94
B. cereus is a ____ cell
S. aureus is a ___ cell
endospore; vegetative
95
___ is the most harmful radiation to bacteria
UVA
96
___ ___ is halotolerant and can withstand higher salt concentrations than ___ ____
___ ___ is a halophile that only grows in high salt concentrations
S. aureus ; E.coli ; H. salinarum
97
grows at moderate salt concentrations
Halotolerant
98
grow best in high salt concentrations (mostly archaea)
Halophile
99
parameter describing water availibilty
Aw (water activity)
100
organisms used in osmotic pressure experiments
S. aureus ; E. coli ; H. salinarum
101
an example of both a selective and differential medium used to grow and help ID Staphylococcus bacteria
MSA media (mannitol salt agar)
102
MSA medium is ____% NaCl
75
103
MRSA stands for
methicillin-resistant staphylococcus aureus
104
Medium that favors colony pigmentation
SM 110 (Staphylococcus Medium 110)
105
Staphylococci infections result from bacteria breaching ___ and ____ ____
skin / mucous membranes
106
_____% of the USA population is a Staphylococci carrier
20-30
107
an infectious disease caused by a pathogen that is resistant to many antibiotics
MRSA
108
The ____ in MSA medium inhibits all but staph growth
NaCl
109
If mannitol is fermented, ___ is produced
If phenol red indicator in MSA turns to yellow, ___ is produced
acid
110
- S. aureus
- S. epidermis
- S. haemolyticus
- S. hominis
- S. saprophyticus
5 pathogenic Staphylococci species
111
how to make yogurt
- bring milk to 87C
- cool milk to 48 C
- add a spoonful of greek yogurt to milk
- incubate at 48 C and transfer to refridgerator
112
S. thermophiles is a ___ bacteria
L. bulgaricus is a ___ bacteria
thermophile ; mesophile
113
- Lactobacillus bulgaricus
- Streptococcus thermophilus
Yogurt bacteria
114
Taste in yogurt depends on the type of ____ bacteria present
lactic (or milk used)
115
- thermophile ( 46-48 C)
- ferments lactose to lactic acid
- lactic acid lowers pH when secreted
- Lactic acid reacts with calcium caseinate --> casein denatures, forming curd (thickness)
S. thermophiles
116
- mesophile
- lactose fermentation occurs in the refrigerator
- more acid-resistant than other bacteria
- refrigeration keeps bacteria from making too much lactic acid
- acid will prevent the growth of any other organisms
L. bulgaricus
117
S. aureus is gram ___
positive
118
E. coli, P. Vulgaris, P. aeruginosa are all gram __
negative
119
antimicrobial impregnated paper disks are placed on plate inoculated to form a bacterial lawn, the plates are incubated and time is given for the agent to diffuse into the agar
Kirby-Bauer method
120
If the organism is susceptible to the antibiotic, a ___ ___ will appear around the disk where growth is inhibited
clear zone
121
1. effects cell wall
2. effects protein synthesis (70s ribosome)
3. effects nucleic acid synthesis (DNA and RNA)
4. effects enzymatic activity (competitive inhibition)
5. injury to the plasma membrane
5 modes of action for antibiotics
122
- S. aureus
- P. aeruginosa
- M. tuburculosis
- N. gonorrhea
- Enterococcus
organisms used for antibiotic resistance
123
an infection acquired within a healthcare setting during the delivery of medical care and is a non-communal infection (1.7 million cases in US)
Healthcare-associated infection (HAI)
124
Antibiotics that affect a broad range of gram-positive or gram-negative bacteria that are used to treat hospital-acquired infections
broad-spectrum antibiotics
125
compounds that kill or inhibit microorganisms
antimicrobials
126
Antimicrobial agent that is produced naturally by a microorganism that inhibits/kills other bacteria
antibiotic
127
antimicrobials that are produced by microorganisms and ALTERED in the lab
semi-synthetic antibiotics
128
antimicrobials that are produced PURELY in the lab
Synthetics antimicrobials
129
area around disc with antimicrobial agent where no growth occurs
inhibition zone
130
substances that can kill microbes but are gentle enough to be applied to living tissue
antiseptics
131
Antiseptics do not destroy _____
They work mostly to prevent infections from ____ skin bacteria
endospores; opportunistic
132
substances that kill microbes and that are harmful to living tissue
disinfectant
133
reduce microbial numbers but do not completely eliminate all microbes
sanitizers
134
In blood agar, S. aureus produces ___ toxin that causes ___ hemolysis
alpha / beta
135
Used as an enrichment medium for fastidious microbes as well as differential media
Blood Agar
136
Partially broken down hemoglobin is released and gives greenish color in medium
alpha hemolysis
137
Complete lysis of red blood cells and gives a clear zone around the colony
beta hemolysis
138
No hemolysis and no change in the blood agar around the colony
gamma hemolysis
139
determine presence of coagulase protein
Coagulate test
140
Coagulase tests and blood agar tests are used on _____ medium
SM 110
141
In coagulate tests, positive tests will show a ___ formation --- negative tests will show ___
clot / liquid
142
S. aureus is coagulate ____
positive
143
The coagulate test is used to determine between Staph ____ and Staph ___
aureus / saphrophyticus
144
In MSA medium, the yellow results are _____.
the red results are ____ and _____.
S. aureus / S. marcescens & S. epidermidis
145
used as an initial tests to identify staphylococci
Blood Agar Test
146
protein derived from animal protein collagen
Gelatin
147
used to determine the ability of an microbe to produce gelatinases / protease that liquifies the gelatin
Gelatin Hydrolysis Test
148
Gelatin Hydrolysis Test results
liquid = ____
remains solid = ___
positive; negative
149
B. cereus is citrate _____
negative
150
endospores are resistant to heat so it takes longer for the heat to kill the endospores
Why does B. cereus take longer to kill under UV light?
151
- time of exposure
- presence of glass /plastic material to block radiation
- endospores are more resistant to UV than vegetative cells
killing properties of UV light depend on
152
- acid-soluble proteins protect DNA by changing shape
- cell repair mechanism is produced by UV
How are endospores more resistant to UV than vegetative cells?
153
A common agar medium used for anti-microbial susceptibility testing
Mueller-Hinton agar
154
- S. aureus (Gram +)
- E. coli (Gram -)
- P. vulgaris (Gram -)
- P. aeruginosa (Gram -)
organisms used for antibiotic sensitivity testing
155
- tetracycline
- gentamicin
- streptomycin
All are antibiotics that effects ___
protein synthesis
156
- penicillin (1st antibiotic)
- cephalothin
- vancomycin (drug of choice for MRSA)
All are antibiotics that effects ___
cell wall synthesis
157
injury to plasma membrane. Used topically. Effective against P. aeruginosa.
Polymyxin B
158
has a biofilm which causes more resistance to bacteria
P. aeroginosa
159
disinfectant that destroys cell wall synthesis, cell membrane, and DNA
hydrogen peroxide
160
disinfectant that destroys cell wall synthesis
bleach
161
antiseptic that inhibits cell membrane (huge resistance)
tea tree oil
162
antiseptic that inhibits enzymatic activity
iodine
163
Capsule stain is a ___ stain and uses ____ dye to stain background and bacterial cell
differential / acidic/basic
164
Capsule is synthesized in ___ and secretes outside of cell
- made of _____
- resistant to ___
cytoplasm / polysaccharides / phagocytosis
165
primary stain for capsule stain: ___
counterstain for capsule stain: ___
crystal violet / cooper sulfate
166
capsule made up of polysaccharides
Glycocalyx
167
extracellular gel-like layer outside cell wall
Capsule
168
- Protective (S. pnemoniae → pneumonia)
- Attachment (S.mutans → dental plaque)
capsule function
169
use crystal violet and cooper sulfate
- all parts of cell take up purple dye
Anthony capsule stain
170
what does cooper sulfate act as in capsule stain?
decolorizer and counterstain
171
washes out crystal violet in cell but does not decolorize the capsule
cooper sulfate
172
- avoid cell shrinking (could cause false positive)
- avoid cell shape changing
- could get false negative because the heat could destroy the capsule
Why is there no heat fix in capsule stain?
173
The purple color in the capsule stain is the ___ ___ stained
cell walls
