Metabolism of Carbohydrates and Organic Acids Flashcards
(361 cards)
1
Q
refers to the set of life-sustaining
chemical transformations within the cells of living
organisms.
A
metabolism
2
Q
refers to the set of life-sustaining
chemical transformations within the cells of living
organisms.
A
metabolism
3
Q
Living things utilize available ___in their
environment to manufacture important subcellular
components.
A
biomolecules
4
Q
Metabolic cycles are ___-DRIVEN reactions
A
ENZYME
5
Q
Biomolecules are ___.
A
nutrients
6
Q
Metabolic cycles are ENZYME-DRIVEN reactions
Biomolecules are nutrients.
These cycles allow microorganisms to fulfill two
important life instincts which are?
A
survival
reproduction
7
Q
is a crucial enzyme in anaerobic metabolism, particularly in bacteria, facilitating the reversible conversion of pyruvate and coenzyme A (CoA) into formate and acetyl-CoA
A
pyruvate formate lyase
8
Q
Available biomolecules are ___or
___ molecules
A
simple
complex
9
Q
Large molecules are often ____by bacteria
to obtain the energy they carry
A
oxidized
10
Q
Metabolism of bacteria often produces ___
useful for determining bacterial identity.
A
byproducts
11
Q
Each bacterial species has a distinct set of ___and
metabolic pathways, leading to the production of specific
byproducts
A
enzymes
12
Q
can be detected using biochemical
tests, which analyze the presence or absence of specific
enzymes or metabolite
A
byproducts
13
Q
is a standardized identification system used to identify Enterobacteriaceae, a group of Gram-negative bacteria commonly found in the intestines. It employs a set of 20 miniaturized biochemical tests, and the results are then compared to a database to determine the bacterial species.
A
API 20E
14
Q
tests performed for metabolism of carbohydrates
A
O/F of Sugars
MRVP Test
Citric Acid Utilziation
Starch Hydrolysis
15
Q
Tests the ability to ferment sugar and convert end
products of glycolysis into gaseous byproducts.
A
basal medium
16
Q
basal medium is a ___ medium
A
differential
17
Q
in basal medium, what is the pH indicator?
A
phenol red
18
Q
if a species is a sugar fermenter, the pH indicator turns
A
yellow
19
Q
formulation of basal medium
A
pancreatic digest of casein
sodium chloride
dipotassium phosphate
bromothymol blue
agar
carbohydrates
20
Q
OF Basal Medium is added with
A
10% dextrose soln without mineral oild overlay
21
Q
Helps in the determination of the pathway utilized
by the organism in fermenting Glucose.
A
methyl red/ voges proskauer
22
Q
is a metabolic pathway utilized by certain bacteria, like Escherichia coli (E. coli), to produce a diverse range of organic acids and other byproducts during anaerobic conditions.
A
mixed acid fermentation
23
Q
in mixed acid fermentation pathway, what does the bacteria generate?
A
acetate
formate
lactate
succinate
ethanol
24
Q
is an anaerobic process where microorganisms convert glucose into 2,3-butanediol, often with other byproducts like ethanol, carbon dioxide, and hydrogen.
A
2,3-butanediol formation
25
2-3 butanediol formation pathway is particularly common in bacteria such as
facultative anaerobic bacteria (Kliebsella and Enterobacter)
26
MRVP Medium content
Buffered peptone
Dipotassium phosphate
dextrose
27
broth remains yellow
broth remains unchanged or turn a copper color
MRVP negative
28
examples of MRVP negative
Kliebsella pneumoniae
Enterobacter aerogenes
29
broth turns red
MRP positive
30
MR positive example
E. coli
Yersinia pestis
31
VP positive
E. aerogenes
32
positive for MR test and inference
red (organism performs mixed acid fermentation)
33
positive for VP test and inference
red (production of acetoin)
34
precursor to 2,3 butanediol fermentation
VP positive
35
Used to determine if an organism can use citrate as
its sole carbon source
Simmon's citrate agat
36
Simmon's Citrate Agar detects the eznyme___
citrase
37
is Simmon's Citrate Agar complex or synthetic?
synthetic
38
simon's citrate agar negative test
green
39
simmons citrate agar positive
blue
40
what turns from green to blue in simmons citrate agar
bromothymol blue indicator
41
if the bromothymol indicator turns blue in the medium, it means there is an ___ in pH
increase (above 7.6)
42
determines whether a microorganism can break down starch into smaller molecules using the enzyme α-amylase.
starch hydrolysis test
43
enzyme used to break down starch
a-amylase
44
Unhydrolyzed starch reacts with iodine, forming what color
blue-black color
45
Hydrolyzed starch does not react with iodine, leaving a ___zone around bacterial growth.
clear
46
A clear zone around bacterial growth indicates starch hydrolysis.
what result
positive
47
The agar remains blue-black, showing that starch was not hydrolyzed.
what result
negative test
48
Used to detect the presence of Cytochrome
Oxidase enzyme
oxidase test
49
Used to identify organisms that produce the
enzyme Catalase which breaks down Hydrogen
Peroxide to water and Oxygen.
catalase test
50
sulfur indole motility medium is used totest the capability of an organism to (3)
reduce sulfur
produce indole
move (motility)
51
is SIM media synthetic or complex?
complex
52
H2S production negative in SIM Media
No blackening of medium
53
H2s production positive in SIM media
blackening of medium (organism produces hydrogen sulfide)
54
indole production negative in SIM media
no pink or red ring after adding Kovac's reagent
55
indole production positive in SIM Media
pink or red ring after adding Kovac's reagent
56
positive indole production means
organism can break down tryptophan to produce indole
57
indole production
organism can break down ___to produce indole
tryptophan
58
Growth is restricted along the stab line, showing the organism is non-motile
what result of SIM media?
motility negative
59
Broth test for the production of the enzyme lysine
decarboxylase, which removes the carboxyl group from
the amino acid Lysine
lysine decarboxylase broth
60
which removes the carboxyl group from
the amino acid Lysine.
lysine decarboxylase
61
is lysine decarboxylase broth synthetic or complex?
complex
62
lysine decarboxylase test positive
microorganism can decarboxylate lysine, producing cadaverine (raises pH and turning the medium purple)
63
a positive lysine decarboxylase test indicate that the microorganism can decarboxylate lysine and procudes
cadaverine
64
cadaverine does what to the medium
raises pH and turns the medium purple
65
a negative lysine decarboxylase test will look like
yellow broth
66
m tests the ability of an
organism to produce the enzyme deaminase.
phenylalanine deaminase
67
are enzymes that remove an amino group (-NH₂) from molecules, typically nucleotides or amino acids.
deaminases
68
phenyl deaminase test agar synthetic or complex?
complex
69
phenylalanine agar positive test
green
70
phenylalanine agar negative test
orange/yellow
71
A green color appears after adding 10% ferric chloride, indicating the presence of phenylpyruvic acid. This is characteristic of Proteus, Providencia, and Morganella species.
positive phenyl deaminase test
72
a positive phenyl deaminase test indicate the presence of
phenylpyruvic acid
73
No color change or a yellow/straw color, meaning the organism does not produce phenylpyruvic acid
negative phenyl aminase test
74
Used to identify bacteria that are capable of hydrolyzing
urea using urease.
Christensen's Urea agar
75
Christensen's Urea agar is used to identify bacteria capable of hydrolyzing ___ using __
urea
urease
76
Christensen's Urea Agar synthetic or complex?
complex
77
an enzyme that hydrolyzes urea into ammonia and carbon dioxide
urease
78
The medium turns bright pink due to the alkalinization caused by ammonia production. This indicates urease activity, commonly seen in Proteus, Klebsiella, and some Yersinia species
positive christensen's test
79
The medium remains yellow or light orange, meaning the organism does not produce urease or does so weakly
what result
negative christensen's urea
80
urease, an enzyme that hydrolyzes urea into
ammonia
carbon dioxide
81
The Christensen's Urea Agar test determines whether a microorganism produces urease, an enzyme that hydrolyzes urea into ammonia and carbon dioxide, __the pH of the medium.
increasing
82
Bacteria metabolize carbohydrates via either
respiration
fermentation
83
Strict ___ produce energy from
carbohydrates only by oxidative phosphorylation (aerobic respiration).
aerobes
84
Strict aerobes produce energy from
carbohydrates only by ___phosphorylation (aerobic respiration).
oxidative
85
carbon metabolism is performed to break down for ___
biosynthesis/energy production
86
is used to differentiate oxidative and
fermentative metabolism of glucose
Hugh and Liefson test
87
The medium
contains rich source of carbon
Hugh and Liefson test
88
Hugh Liefson Test pH indicator
bromothymol blue
89
color of bromothymol blue under alkaline-oxidative conditions
green/blue
90
color of bromothymol blue under acidic-fermentative conditions
yellow
91
Each test organism is
inoculated into two tubes of glucose O/F medium. One tube is overlaid with
___, while the other is not.
vaspar
92
serves as a barrier to oxygen to
help achieve an anaerobic environment
vaspar
93
A
positive carbohydrate utilization test is indicated by the
development of a ___color in the medium
yellow
94
Development of a yellow coloration in the open tube only (o/f test) means?
oxidative +
95
Development of a yellow coloration in both open and
closed tubes in o/f test
fermentative
96
A negative carbohydrate utilization test is
indicated by the absence of a ___ color (media remains green or
turns blue).
yellow
97
are frequently
employed for identification of enteric bacteria that include Klebsiella,
basic
carbon metabolism to break down for biosynthesis/energy reproduction
Enterobacter, and Escherichia coli
MRVP
98
Most heterotrophic bacteria can utilize
___for their energy demands.
sugars
99
___ ___ fermenters such as E. coli
ferment glucose to produce large amounts of acetic, formic, and succinic
acids as end products.
mixed acid
100
The large amount of acid produced ___the pH of
the medium to below 5.0.
lowers
101
By using the indicator ___ ___(MR), the
production of these acids as an end product of fermentation can be
monitored in MRVP test
methyl red
102
If the pH drops below 4.5, the color of the methyl red indicator
will be ___(a positive result).
red
103
If the pH drops below ___, the color of the methyl red indicator
will be red (a positive result).
4.5
104
If the pH is above __, the color will be
yellow/orange (negative).
6.0
105
If the pH is above 6.0, the color will be
___ negative).
yellow/orange
106
Enterobacter and Serratia will form products such as ___ and___ rather than the large amount of acid, as does Escherichia coli.
ethanol
2,3-butanediol
107
These reactions can be used to differentiate some common gram-negative
rod-shaped organisms.
vogues proskauer test
108
vp test detects the presence of
acethylmethylcarbinol
109
After ______ are added, a pink
color developing after a few minutes indicates the presence of
acetylmethylcarbinol, and the test is positive.
Barritt's reagents
110
After Barritt’s reagents are added, a ___ color developing after a few minutes indicates the presence of
acetylmethylcarbinol, and the test is positive.
pink
111
If present, acetylmethyl
carbinol is converted to diacetyl in the presence of ___, strong alkali
(40% KOH), and atmospheric oxygen.
a- naphthol
112
presence of ∝- naphthol, strong alkali
(40% ___), and atmospheric oxygen.
KOH
113
was not part of the
original procedure but was found to act as a color intensifier by Barritt and
must be added first.
a-naphthol
114
The diacetyl and quanidine-containing compounds
found in the ___of the broth then condense to form a pinkish red
polymer.
peptones
115
The ___ and ___-containing compounds
found in the peptones of the broth then condense to form a pinkish red
polymer in MRVP test
diacetyl
quanidine-containing compounds
116
positive rxn of VP test
pink-red color at the surface
117
negative rxn of VP test
A lack
of a pink-red color (or copper color)
118
weak positive of VP test
rust color
119
is used to test for the utilization of
citrate as sole source of carbon, and ammonium salts as source of
nitrogen
Simmon's citrate agar
120
The Simmon's Citrate Agar is used to test for the utilization of
__ as sole source of carbon, and ammonium salts as source of
nitrogen.
citrate
121
The Simmon's Citrate Agar is used to test for the utilization of
citrate as sole source of ___, and ammonium salts as source of
nitrogen.
carbon
122
The Simmon's Citrate Agar is used to test for the utilization of
citrate as sole source of carbon, and ___ ___ as source of
nitrogen.
ammonium salts
123
The Simmon's Citrate Agar is used to test for the utilization of
citrate as sole source of carbon, and ammonium salts as source of
___.
nitrogen
124
Citrate is
transported into the cell in the fully protonated state as
citric acid
125
citric acid is a ___ acid
tricarboxylic
126
Removal of H+ from the medium decreases the acidity
and ___the pH. T
raises
127
The ___in pH is detected by the color change in the
bromothymol blue indicator present in the medium from green to a deep
blue
rise
128
positive result of Simmon's citrate agar is an indication that the organism is utilizing ___
citrate
129
is to determine if a microorganism
can use malonate as its sole source of carbon and energy for growth.
malonate test
130
the malonate
test medium contain
sodium malonate
131
The
test medium contains sodium malonate, a small amount of glucose, and
inorganic ammonium salts as source of ___
nitrogen
132
When the bacterium
ferments malonate what are formed,
which increases the alkalinity of the medium.
sodium hydroxide and sodium bicarbonate
133
indicator in malonte test
bromothymol blue
134
Malonatenegative organisms that ferment glucose render the medium
acidic, turning the indicator ___
yellow
135
malonate test negative has what pH and color
acidic (yellow)
136
malonate test positivehas what pH and color
blue (basic)
137
A negative malonate test is indicated by the media remaining
green or turning yellow due to
___fermentation.
dextrose
138
which will use water to
break apart organic molecules such as the carbohydrate starch.
hydrolases
139
he large
polysaccharide molecule starch contains two parts,
amylose
amylopectin
140
amylose and
amylopectin, these are rapidly hydrolyzed using a hydrolase called
a-amylase
141
The large
polysaccharide molecule starch contains two parts, amylose and
amylopectin, these are rapidly hydrolyzed using a hydrolase called alphaamylase to produce smaller molecules: (3)
dextrin
maltose
glucose
142
can be used to indicate the presence of
starch, when it contacts starch, it forms a blue to brown complex.
gram's iodine
143
If the
starch has been broken down/hydrolyzed, then there is a ___ area that
appears in the medium upon addition of Gram's iodine
clear
144
The ability of an organism to oxidize ___as sole carbon source
to gluconate is a useful characteristic in the identification of pseudomonads.
gluconates
145
The ability of an organism to oxidize gluconates as sole carbon source
to gluconate is a useful characteristic in the identification of ___.
pseudomonads
146
Microorganism is grown in Hayne's Medium, which contains ___
potassium
147
Microorganism is grown in ___ Medium, which contains potassium
Hayne's medium
148
nonreducing compound in Hayne's medium
gluconate
149
reducing compound in Hayne's medium
gluconate
150
The change from gluconate, (a nonreducing
compound) to gluconate (a reducing compound) is tested usin
Benedict's reagent
151
The __ions in the reagent are reduced to __ ions by the
free ketone group of 2-ketogluconate and an orange yellow precipitate of
Cu2O results
cupric
cuprous
152
The cupric ions in the reagent are reduced to cuprous ions by the
free ketone group of ____and an orange yellow precipitate of
Cu2O results (
2-ketogluconate
153
A. Oxidation and/or Fermentation of Sugars
Stab inoculate P. fluorescens and E. col into ___ and ___ medium
using two tubes per sugar.
Hugh and Liefson
153
The cupric ions in the reagent are reduced to cuprous ions by the
free ketone group of 2-ketogluconate and an orange yellow precipitate of
___ results
Cu2 O
154
. Seal the surface of one set of the tubes with vaspar or water agar to
a ___ height.
5mm
155
is usually used because some bacteria can degrade
agar.
vaspar
156
Vaspar is usually used because some bacteria can degrade
agar. For class purposes, ____ agar can be used instead
2% water agar
157
Change of color from light blue to yellow indicates
___production.
OF test
acid
158
. If acid is produced in open tube only (without agar
plug), metabolism is ___
oxidative
159
if in both tubes, metabolism is
___.
fermentative
160
Fermentation is ___when it is accompanied by
gas production and ___ when there is no gas produced.
aerogenic
anaerogenic
161
produces acid from carbohydrates under aerobic condition only
oxidative bacteria
162
(that produces acid both under aerobic and anaerobic conditions)
fermentative bacteria
163
microorganisms degrade glucose either fermentatively or oxidatively.
saccharolytic
164
However, the acids formed in ___degradation of glucose are extremely weak and less, and the more sensitive
oxidative
165
The ___determines if certain gram-negative rods metabolize glucose by fermentation or aerobic respiration (oxidatively).
oxidative fermentative test
166
During the anaerobic process of fermentation, ___is converted to a variety of mixed acids depending on the type of fermentation.
pyruvate
167
The high acid concentration produced during fermentation will turn the bromthymol blue indicator in OF media from green to ___ in the presence or absence of oxygen.
yellow
168
Certain nonfermenting gram-negative bacteria metabolize glucose using aerobic respiration and only produce a small amount of weak acids during ___and the ___ cycle.
glycolysis
Krebs
169
The decreased amount of ___ and increased amount of ___ facilitates the detection of weak acids thus produced in OF test
peptone
glucose
170
is added to further promote acid detection in OF test
dipotassium phosphate buffer
171
cannot use the carbohydrate in the media
nonsaccharolytic
172
Glucose Fermenter example
E.coli
173
Glucose oxidizer
P. aeruginosa
174
Nonsaccharolytic example
Moraxella species
175
B. Methyl Red (MR) and Voges-Proskauer (VP) Test
Transfer 1 mL of the culture to a tube and add 1-2 drops of ___ ___
methyl red
176
B. Methyl Red (MR) and Voges-Proskauer (VP) Test
Transfer 1 mL of the culture to a tube and add __drops of methyl red indicator
1-2 drops
177
To the rest of the medium, add 5 drops of ___and
mix. Then add 7-10 drops of 40% KOH, mix, and stand for 15-20 min.
Pink to red color is positive VP reaction indicating acetoin production;
no change is negative.
5% alpha-naphthol
178
To the rest of the medium, add 5 drops of 5% alpha-naphthol and
mix. Then add 7-10 drops of 40% ___, mix, and stand for 15-20 min.
Pink to red color is positive VP reaction indicating acetoin production;
no change is negative.
KOH
179
Pink to red color is ___ VP reaction indicating acetoin production;
no change is ___.
positive
negative
180
Pink to red color is positive VP reaction indicating ___production;
no change is negative.
acetoin
181
expected MRVP results of E coli
MR +
VP -
182
expected MRVP results of E. faecalis
MR -
VP +
183
and shift of the green color to
____ ___color means positive utilization of citrate.
citric acid utilization
prussian blue
184
The citrate utilization test is commonly employed as part of a group of tests called the
IMViC
185
IMViC means
Indole
Methyl Red
VP
Citrate
186
____ can be used to distinguish between coliforms such as Klebsiella aerogenes (formerly Enterobacter aerogenes) (+ve) which occur naturally in the soil, and aquatic environments from fecal coliforms such as Escherichia coli (-ve), whose presence would be indicative of fecal contamination.
citrate utilization
187
Citrate utilization can be used to distinguish between ___such as Klebsiella aerogenes (formerly Enterobacter aerogenes) (+ve) which occur naturally in the soil, and aquatic environments from fecal coliforms such as Escherichia coli (-ve), whose presence would be indicative of fecal contamination.
coliform
188
Citrate utilization can be used to distinguish between coliforms such as Klebsiella aerogenes (formerly Enterobacter aerogenes) (+ve) which occur naturally in the ___, and aquatic environments from fecal coliforms such as Escherichia coli (-ve), whose presence would be indicative of fecal contamination.
soil
189
Citrate utilization can be used to distinguish between coliforms such as Klebsiella aerogenes (formerly Enterobacter aerogenes) (+ve) which occur naturally in the soil, and aquatic environments from ___coliforms such as Escherichia coli (-ve), whose presence would be indicative of fecal contamination.
fecal
190
Citrate utilization can be used to distinguish between coliforms such as Klebsiella aerogenes (formerly Enterobacter aerogenes) (+ve) which occur naturally in the soil, and aquatic environments from fecal coliforms such as Escherichia coli (-ve), whose presence would be indicative of fecal ___.
contamination
191
When an organic acid such as citrate (remember Krebs cycle) is used as a carbon and energy source, alkaline carbonates and bicarbonates are produced, ___ the medium’s pH, resulting in the color change.
increasing
192
Utilization of exogenous citrate requires the presence of citrate transport proteins (permeases). Upon uptake by the cell, ___ is cleaved by citrate lyase to oxaloacetate and acetate. The oxaloacetate is then metabolized to pyruvate and CO2.
citrate
193
Utilization of exogenous citrate requires the presence of citrate transport proteins (permeases). Upon uptake by the cell, citrate is cleaved by citrate lyase to ___ and ___ The oxaloacetate is then metabolized to pyruvate and CO2.
oxaloacetate
acetate
194
A. Under alkaline conditions, pyruvate is metabolized to ___ and ___.
acetate
formate
195
At pH 7.0 and below, what are also produce in citrate utilization test.
lactate
acetoin
196
The released carbon dioxide will subsequently react with water and the sodium ion in the medium to produce ___
sodium carbonate
197
The released carbon dioxide will subsequently react with water and the sodium ion in the medium to produce sodium carbonate, an alkaline compound that will ___ the pH.
raise
198
major class of naturally occuring organic compounds which have approximately the general formula of (CH2O)n
carbohydrates
199
four major classes of carbohydrates
Monosaccharide
Oligosaccharide
Polysaccharide
Disaccharide
200
building block of carbohydrates
monosaccharide
201
short chains of monosaccharide units (ex. present in cell membrane)
oligosaccharide
202
three major pathways for utilization of carbohydrates
fermentation
aerobic respiration
anaerobic respiration
203
polyhydroxy means
multiple OH
204
glucose is an ___
aldehyde
205
fructose is a ___
ketose
206
carbohydrates serve as both electron donor and electron acceptor, oxidation occurs in the absence of electron transport chain
does not require oxygen
fermentation
207
energy from electron transport is used to generate ATP, involves ETC and oxygen is the final electron acceptor
aerobic respiration
208
involves essentially the biochemical pathways as aerobic respiration except for the terminal electron acceptor
anaerobic respiration
209
anaerobic respiration has what as the terminal electron acceptor
nitrate
sulfate
CO2
210
alcoholic fermentation will convert pyruvate to ___
ethanol
211
byproducts of alcoholic fermentation
CO2
NAD+
212
pyruvate is converted to __ in lactic acid fermentation
lactic acid
213
by product of lactic acid fermentation
NAD+
214
used for detecting oxidative and fermentative carbohydrate degradation
O/F test
215
OF test is proposed by ___ in 1953
Hugh and Liefson
216
OF test is proposed by Hugh and Liefson to classify
Gram-negative bacteria
217
a carbohydrate is added to the medium, degradation of carbohydrate to acid is indicated by pH indicator called
bromothymol blue
218
degradation of carbohydrates indicates the changing of OF from ___ to ___
green
yellow
219
tube of OF tube is sealed with (3)
water agar
vaspar
mineral oild
220
acidic OF test means what pH
acidic
221
bacteria that cannot metabolize carbohydrate
nonsaccharolytic
222
some bacteria utilize glucose to form large amounts of acid such as
acetic
formic
succinic
223
bacteria utilizing glucose to form acid will result in the media to what pH
below 4.4
224
pH indicated in MR test
methyl red
225
MR test
pH is >5.1, what color
yellow
226
MR test
pH is <4.4, what color
red
227
Baritt's reagent
a-naphthol
228
O2, KOH, and A-naphthol react with acetoin to produce
diacetyl
229
product of acetoin and Baritt's reagent
diacetyl
230
reacts with creatine of free NH2 of guanidine moiety to form a red complex
diacetyl
231
what is required for the formation of diacetyl
oxygen
232
Barritt's A reagent component
a-naphthol in ethanol
233
Baritt's B reagent
40% potassium hydroxide
234
metabolism of citrate leads to __
alkalinization
235
bromothymol blue, indicator of citrate utilization test turns ___ when neutral
green
236
bromothymol blue, indicator of citrate utilization test turns ___ when acidic
yellow
237
bromothymol blue, indicator of citrate utilization test turns ___ when basic
blue
238
organisms that metabolize citrate usually have ___ to transfer citrate across cell membrane
permease
239
enzyme that will act on citrate to produce oxaloacetate and acetate
lyase
240
will then be decarboxylated to pyruvate and CO2
oxaloacetate
241
in citrate utilization test, excess ___ leads to alkaline pH
CO2
242
pH indicator of malonate utilization test
bromothymol blue
243
malonate is converted to ___ with the release of CO2
acetate
244
malonate is converted to acetate with the release of ___
CO2
245
excess CO2 causes what
release of ammonium salts
246
positive malonate test
blue
247
negative malonate test
green or no color change
248
complex polysaccharide composed of amylose and amylopectin
starch
249
amylose complexes with iodine formin a __ structure around iodine
helical
250
in iodine-amylose complex, iodine exhibits a strong __ of light
absorption
251
reddish brown starch hydrolysis test means
starch is hydrolyzed into 8 to 12 glucose units (e.g. dextrins)
252
8 to 12 glucose units
dextrins
253
no color/cleared color in starch hydrolysis test
<7 glucose units (maltose glucose)
254
starch hydrolysis test differentiates
bacillus
clostridiu
255
reducing sugar derivative from glucose metabolism
2-ketogluconate
256
medium of 2-ketogluconate production
Hayne's medium
257
enzyme that converts gluconate to 2-ketogluconate
gluconate dehydrogenase
258
organisms with this enzyme can enter other carbon sources via Entner-Doudoroff pathway
gluconate dehydrogenase
259
organisms with gluconate dehydrogenase can enter other carbon sources via
Entner-Doudoroff Pathway
260
the 2-ketogluconate accumulated in the medium will react with the ___ in the Benedict's reagent
CU2+
261
the 2-ketogluconate accumulated in the medium will react with the Cu2+ in the ___ reagent
Benedicts
262
the 2-ketogluconate accumulated in the medium will react with the Cu2+ in the Benedict's reagent in the presence of __ and __
heat
alkali
263
the 2-ketogluconate accumulated in the medium will react with the Cu2+ in the Benedict's reagent in the presence of heat and alkali to form
cuprous oxide (CU2O)
264
the 2-ketogluconate accumulated in the medium will react with the Cu2+ in the Benedict's reagent in the presence of heat and alkali to form Cuprous oxide as what color
yellow orange
orange-red
265
benedicts test
absence of reducing sugar
what color
blue
266
benedicts test
presence of reducing sugar (weak)
what color
green
267
benedicts test
absence of reducing sugar (moderate)
what color
orange
268
benedicts test
absence of reducing sugar (strong)
what color
brick red
269
example of non reducing sugar
sucrose
270
Glucose OF Result
P.aeruginosa
With Agar-
Without Agar -
inference?
Without - Yellow (Oxidative)
With - Yellow, green
oxidative
271
Glucose OF Result
E.coli
With Agar-
Without Agar -
inference?
fermentative
272
Lactose OF Result
P.aeruginosa
With Agar-
Without Agar -
inference?
with - (yellow with minute green
without - yellow minute green
still suggest oxidation
273
Lactose OF Result
E.coli
With Agar-
Without Agar -
inference
w/o - yellow
w/ - yellow (slight green)
fermentative
274
mannitol OF Result
p. aeruginosa
Without Agar -
With Agar-
inference
w/o - yellow orange
w/ - yellow
oxidative
275
mannitol OF Result
E.coli
Without Agar -
With Agar-
inference
w/o - light blue
w/ - yellow
negative
276
sucrose OF Result
E.coli
Without Agar -
With Agar-
inference
w/o - yellow
w. - yellow
fermentative
277
sucrose OF Result
p. aeruginosa
Without Agar -
With Agar-
inference
oxidative
w/o orange
w/ yellow
278
MRVP test interpet
E. coli MRVP
MR +
VP -
279
MRVP test
E. faecalis
MR -
VP +
280
SCA results
E.coli
inference?
negative (green)
citrate not utilized
281
SCA results
E.aerogenes
inference?
Blue green (+)
citrate utilized
282
Malonate utilization
E. coli
inference?
negative (green)
lacks enzyme to utilize malonate
283
Malonate utilization
P. fluorescens
color change from green to blue
result and inference?
The blue color indicates the
ability of P. fluorescens to
metabolize malonate,
producing alkaline
byproducts that shift the pH
indicator
284
Growth area and
surrounding medium turned
blue-black or dark brown
once filled with iodine
for E.coli
starch hydrolysis results?
E. coli does not hydrolyze
starch; no amylase enzyme
produced
285
Clear zone around growth,
while the rest of the plate
turns blue-black or dark
brown when filled with
iodine
for B.subtilis
starch hydrolysis results?
B. subtilis hydrolyzes
starch; amylase enzyme is
produced
286
No precipitate
forms
for 2-ketogluconate production of E.coli
result, inference?
Organism lacks enzymatic machinery to
oxidize potassium gluconate to 2-
ketogluconate
287
Brownish orange
precipitate forms
for 2-ketogluconate production of P. fluorescens
result, inference?
Potassium gluconate has been oxidized to
potassium 2-ketogluconate
288
Why are some microorganisms capable of utilizing certain carbohydrates and some
are not?
Microorganisms are only capable of using certain carbohydrates because of
certain genes that help in producing the necessary enzymes to breakdown and
metabolize these carbohydrates. Some are not able to utilize certain carbohydrates
because of the absence of the said components: genes, enzymes, or transporters.
289
H. What is the importance of adding vaspar or water agar to one of the inoculated tubes
of Hugh and Leifson medium?
The importance of adding vaspar or water agar to Hugh and Leifson (HL) medium
provides anaerobic conditions, enabling bacteria to be differentiated based on whether
they oxidize or ferment glucose. When glucose is metabolized in the presence of oxygen,
oxidative bacteria produce acid in the open tube and become yellow in the sealed tube.
Fermentative bacteria can metabolize glucose in the presence and absence of oxygen,
producing acid and yellowing of tubes. On the other hand, non-utilizers may not
metabolize glucose at all, producing alkaline byproducts in both tubes. Observing color
changes in open and sealed tubes allows one to detect the organism's primary method
of glucose metabolism, which is a key characteristic for bacterial identification and
classification.
290
I. Does a bacterium use the same metabolic pathway for utilization of carbohydrate (like
glucose) and organic acids? Explain your answer.
The metabolic pathways bacterium use for utilization of carbohydrate and organic
acids varies due to their distinct chemical structures and energy requirements.
Carbohydrates, like glucose, are typically processed through glycolysis, or other
alternative pathways such as the Entner-Dourdoroff pathway, or the pentose phosphate
pathway, breaking down sugars into pyruvate while generating ATP and electron carriers.
Organic acids, such as acetate or fatty acids, are metabolized by specialized routes like
β-oxidation for fatty acids, or bypassing glycolysis through direct entry into the
tricarboxylic acid (TCA) cycle. The pathways for organic acids involve unique enzymes,
while glycolysis relies on hexokinases and phosphofructokinases. The TCA cycle
becomes a common hub for further energy extraction from acetyl-CoA derived from both
organic acids and pyruvate from glucose. The varied pathways allow bacteria to efficiently
adapt their metabolism to diverse carbon sources in varying environments.
291
. Where will a bacterium grow best: glucose, malonate, or gluconate? Explain your
answe
A bacterium’s growth preference will depend on its metabolic capabilities and the
nutrients available in the culture media. Glucose, being the universally preferred carbon
source, supports many bacteria since it can be easily metabolized through glycolysis and
provides efficient energy. Most bacteria have the enzymes to process glucose, which
makes it a common choice. Malonate, on the other hand, can be a less favorable carbon
source for most bacteria since it requires the presence of enzymes such as the malonylCoA decarboxylase to metabolize. Thus, only those bacteria that can effectively utilize
this can grow and even then, energy yield is relatively low compared to glucose. Lastly,
gluconate can be metabolized by bacteria via the Entner-Doudoroff pathway but is still
less efficient that glucose in providing energy. Therefore, most bacteria will grow best on
glucose due to it being a universal metabolic carbon source while some bacterial strains
might be able to thrive on malonate or gluconate depending on its enzymatic capabilities.
292
All of the chemical reactions and physical
occurings within a living organism
metabolism
293
Bacteria obtain the energy and nutrients (e.g.
carbon) it needs to live and reproduce by
metabolism
294
Metabolic functions are often performed by
several enzymatic reactions in a series or ___
pathway
295
Presence of oxygen
Final electron acceptor
is molecular oxygen
aerobic respiration
296
Type of phosphorylation
used to generate a ATP
Substrate level and
oxidative phosphorylatio
aerobic respiration
297
Absence of oxygen
Final electron acceptor
is inorganic substance
E.g- nitrate ,sulphate
but not oxygen
Substrate level and
oxidative phosphorylation
anaerobic respiration
298
Aerobic/anaerobic
Final electron acceptor is
organic substance.
E.g ethanol, lactic acid
Substrate level
phosphorylation
fermentation
299
The primary
purpose is to
synthesize АТР
for the cell to use
anaerobic respiration
300
The primary
purpose is to
regenerate
NADP+ for
glycolysis.
fermentaion
301
plays a key role in Electron Transport Chain duringaerobic respiration
oxidase
302
catalyzes the oxidation of reduced Cytochrome bymolecular oxygen (O2
), resulting in the formation of H2O and H2O2.
cytochrome oxidase
303
* Cytochrome Oxidase catalyzes the oxidation of reduced Cytochrome bymolecular oxygen (O2
), resulting in the formation of
water and hydrogen peroxide
304
Aerobic as well as some facultative anaerobes and microaerophillicbacteria shows ___ activity
oxidase
305
2 oxidized cytochrome C will react with ___ to produce 2 reduced cytochrome C (wurster's blue)
p-aminodimethylalanine oxatate
306
2 oxidized cytochrome C will react with p- aminodimethyalanine to produce 2 reduced cytochrome C (___blue)
wurster's
307
To determine the ability of microbes to ferment carbohydrates with the production of an acid and/or gas
sugar fermentation test
308
are metabolized through different metabolic pathways depending on typesof microbial species and aerobic or anaerobic environment
sugars
309
If fermenting bacteria are grownin a liquid culture medium containing the carbohydrate, they may produce ___acids asby-products of the fermentation.
organic acids
310
if a pH indicator such as ____ or ___e is included in themedium, the acid production will change the medium from its original color to yellow.
phenol red
bromocresol blue
311
Gases produced during the fermentation process can be detected by using a small,inverted tube, called a D
durham tube
312
If the medium changes from colorless to yellow and gas bubble is found in Durham’s tubethen it indicates
acid and gas formation
313
To differentiate among and between the members ofEnterobacteraceae family
triple sugar iron agar test
314
It is also used to distinguish the Enterobacteriaceae from other gramnegative intestinal bacilli (by their ability to catabolize glucose, lactose, or sucrose, and to liberate sulfides from ferrous ammonium sulfate or
sodium thiosulfate. )
triple sugar iron agar test
315
slants contain a 1% concentration of lactose and sucrose, and 0.1% glucose.
TSI agar
316
indicator of TSI agar
phenol red
317
are the fermentablecarbohydrates. in TSI agar (3)
lactose
sucrose
dextrose
318
make H2S indicatorsystem in TSI agar
sodium thiosulfate
ferrous sulfate
319
Thiosulfate is reduced to H2S by several species of bacteriaand H2S combines with and form what precipitate
insoluble black
320
* Blackening usually occurs in butt of tube in what agar test
TSA agar?
321
The indicator is ___at alkaline pH and yellow at acidic pH, at neutral pH it remains red.
TSI agar
pink
322
The indicator is pink at alkaline pH and __at acidic pH, at neutral pH it remains red.
TSI agar
yellow
323
Yellow butt (A) and red slant (K) in TSU tube mean
fermentation of glucose(phenol red indicator turns yellow due to the persisting acid formation inthe butt).
The slant remains red (alkaline) (K) because of the limitedglucose in the medium and, therefore, limited acid formation, which doesnot persist.
324
A yellow butt (A) and slant (A) d means
fermentation of lactoseand/or sucrose (yellow slant and butt due to the high concentration ofthese sugars) leading to excessive acid formation in the entire medium.
325
noted by splitting of the agar in TSI agar
gas formation
326
seen by blackening of the agar in TSI
gas formation (h2s formation)
327
Red butt (K) and slant (K) means
indicates that none of the sugars werefermented and neither gas nor H2S were produced.
328
Alkaline slant acidic butt in TSI agar means
glucose is fermented
329
Acidic slant/acidic butt means in TSI agar
lucose, sucrose and lactose all 3 sugars are
femented.
330
Bubbles or crack present in TSI agar
gas production
331
Black precipitate present in TSI agar
H2s production
332
view tsi agar test
+1
333
To differentiate E.coli and E.aerogen and to determine the ability ofmicrobes to oxidize glucose with production and stabilization of high content ofacid end produc
methyl red test
334
This test determines the capability of some organisms to produce non-acidic or neutral end products, such as acetyl methyl corbinol (acetoin), from the organic acid that results from glucose metabolism
VP test
335
VP test characterizes
E. aerogenes
336
Development of ____ colour indicates positive test for E.aerogen.
crimson red
337
This test is done on slants since ___
is necessary for citrate utilization
O2
338
If an organism is capable of utilizing sodium malonate as its sole carbon
source, and the same time utilizes ammonium sulphate as its nitrogen sourceе,
an alkaline reaction is produced by the formation of ___
NaOH
339
It is widely used for the differentiation of Enterobacter and Escherichia coli
based on the use of malonate.
malonate utilization
340
catalyze the splitting of organic molecules into smaller molecules in the presence of water.
hydrolases
341
an unbranched glucose polymer (200 to 300 units)
amylose
342
a large branched polymer
amylopectin
343
Obligate aerobes and facultative anaerobes usually containthe enzymes ___which catalyzes thedestruction of superoxide
superoxide dismutase
344
catalyze the destruction ofhydrogen peroxide
catalase
peroixdase
345
Development of ___
___ colour at the interface of the reagent and the broth, within seconds after adding the Kovacs’ reagent indicates the
presence of indole and the test is positive.
cherry red
346
Development of cherry red colour at the interface of the reagent and the broth, within seconds after adding the __’ reagent indicates the
presence of indole and the test is positive.
kocav;s
347
To determine the ability of some microbes to reduce nitrate (NO3
-
) to nitrites (NO2-)or beyond the nitrite stage.
nitrate reduction test
348
Certain organisms like Chemolithoautotrophic bacteria and many chemoorganoheterotrophscan use ___(NO3
-
) as a terminal electron acceptor during anaerobic respiration.
nitrate
349
In this process, nitrate is reduced to nitrite (NO2
-
) by n
nitrate reductase
350
* Examined for the presence of gas and nitrite ions in the medium what test
nitrate reduction test
351
positive nitrate reduction test is colored
red
352
is diamide carbonic acid often referred as carbamide.
urea
353
* The hydrolysis of urea is catalysed by specific enzyme urease to yield2 moles of
ammonia
354
attacks the nitrogen and carbon bond in urea and formsammonia.
urease
355
urease test medium has the pH indicator
phenol red
356
* Splitting of urea creates the alkaline condition which turns phenol redto deep ___in colour
pink
357
Mainly used for identification of Proteus spp. from other genus oflactose nonfermenting enteric organisms.
urease test
358
If __is present in the medium, then it will be degraded which creates alkaline condition in the medium which result in
colour change from reddish pink to deep pink
urea
359
are high molecular weight compounds possessing large amounts of stored energy.
lipids
360
Triglycerides are hydrolyzed by the enzymes called
lipases
