Lab Final Flashcards
1
Q
the sum of the reactions that are associated with the life of a cell
A
metabolism
2
Q
biological catalysts that allow spontaneous unfavorable reactions to occur; convert substrates to products
A
enzyme
3
Q
degrade large molecules outside of the cell into units that are small enough to be transported across the cell membrane
A
exoenzymes
4
Q
degrade large molecules to simpler molecules releasing energy or synthesizing molecules that are needed by the cell
A
endoenzymes
5
Q
enzymes that are produced only if its substrate is available, in an effort to conserve the cell’s energy
A
inducible or adaptive enzymes
6
Q
enzymes that are essential to the cell, so they are produced at all times
A
constitutive enzymes
7
Q
Hydrogen peroxide is a byproduct of what kind of metabolism?
A
aerobic
8
Q
What are the substrates, products, and reagent/indicator for a catalase test?
A
Substrate: hydrogen peroxide
Products: water and O2
Reagent/Indicator: hydrogen peroxide
9
Q
What organism was tested to be catalase positive? Catalase negative?
A
Positive: Staphylococcus epidermis
Negative: Streptococcus mutans
10
Q
What type of bacteria is usually catalase Positive? Negative?
A
Positive: aerobic bacteria
Negative: fermentative or anaerobic bacteria
11
Q
test used to differentiate medically relevant genera by seeing if cytochrome oxidase is produced by microbes
A
oxidase tests
12
Q
What are the substrates, products, reagent/indicator, and media for an oxidase test? What does a positive result look like?
A
Substrate: O2 Product: water Reagent/Indicator: oxidase reagent Media: TSA plate Positive Result: immediately turns microbe blue/purple
13
Q
What organism was tested to be oxidase positive? Oxidase negative?
A
Positive: Pseudomonas putida
Negative: E. coli
14
Q
What kind of cells make oxidase enzymes?
A
cells that do respiration
15
Q
transfers electrons to O2 to from water or hydrogen peroxide as the final electron transfer in electron transport of aerobic respiration
A
cytochrome oxidase
16
Q
(CH2O)_n
A
carbohydrates
17
Q
single molecule of a sugar (ex. glucose)
A
monosaccharide
18
Q
polymers of glucose (ex. cellulose, starch)
A
polysaccharide
19
Q
enzyme that hydrolyzes start into glucose to be transported into a cell for metabolism
A
amylase
20
Q
commercial and industrial uses of microbially produced amylases
A
food, fermentation, brewing, distilling, textiles, paper, etc
21
Q
What links cellulose?
A
Beta-1,4
22
Q
What links starch and glycogen?
A
Alpha-1,4
23
Q
What are the substrates, products, reagent/indicator, and media for an amylase test? What does a positive result look like?
A
Substrate: Polysaccharide (starch) Products: Oligosaccharides of glucose Reagent/Indicator: iodine Media: starch agar plate Positive Result: zone of hydrolysis
24
Q
What organism tested positive for the amylase test? Negative?
A
Positive: Bacillus subtilis
Negative: E. coli
25
enzyme that hydrolyzes cellulose into glucose to be transported into the cell for metabolism
cellulase
26
Where is cellulose found?
eukaryotic (plant and algae) cell walls
27
What are the substrates, products, reagent/indicator, and media for a cellulose test? What does a positive result look like?
Substrate: polysaccharide (cellulose)
Product: oligosaccharides of glucose
Reagent/Indicator: none
Media Used: Dubos broth and agar with paper
Positive Result: plate turns yellow; broth shows paper degradation
28
Why was Cytophaga hutchinsonii used in the cellulase test?
aerobic degradation of cellulose in paper samples
29
amino acids joined by peptide bonds
protein
30
short chain of amino acids
peptide
31
enzymes that degrade proteins
proteases
32
commercial uses of proteases
laundry detergent, stain remover, meat tenderizer
33
milk protein
casein
34
how do you test for caseinase?
milk agar (nutrient agar + skim milk)
35
protein from bones of animals
gelatin
36
how do you test for gelatinase?
gelatine agar (nutrient agar + gelatin)
37
What are the substrates, products, reagent/indicator, and media for a caseinase test? What does a positive result look like?
```
Substrate: Milk
Product: Pepties
Reagent/Indicator: none
Media: Milk Agar
Positive result: Zone of Hydrolysis
```
38
What organisms tested positive in the caseinase test? Negative?
Positive: Bacillus subtilis
Negative: E. coli
39
What are the substrates, products, reagent/indicator, and media for a gelatinase test? What does a positive result look like?
```
Substrate: Gelatin
Product: Peptides
Reagent/Indicator: HCl
Media: Gelatin Agar
Positive result: Zone of Hydrolysis
```
40
What organisms tested positive in the gelatinase test? Negative?
Negative: E. coli
Positive: Bacillus subtilis
41
Can catabolism occur by fermentation or respiration?
both
42
common to fermentation & respiration; conversion of glucose to pyruvate
glycolysis
43
What decides if respiration will occur vs. fermentation
if a terminal electron acceptor is present, respiration will occur
44
Fermentation products (general)? Fermentation products in lactobacillus and saccharomyces?
General: CO2, acids, alcohol, etc.
Lactobacillus: lactic acid
Saccharomyces: alcohol and O2
45
How do you test if an organic is able to ferment a carbohydrate?
Use nutrient broth with 1 fermentable carbohydrate and a pH indicator. Inoculate organism and if it can ferment carbohydrate it will produce acid from fermentation (drops pH and turns broth yellow)
46
How does phenol red work?
Red at pH 7
| Yellow below pH 6.9
47
What will be the result if an organism can ferment carbohydrates?
It will produce acid which drops the pH turning the broth yellow
48
2 amino acids that contain sulfur
cysteine & methionine
49
What happens when cysteine desulffhydrase cleaves sulfydryl group from cysteine?
releases hydrogen sulfide gas
50
What are the substrates, products, reagent/indicator, and media for a cysteine desulfhydrase test? What does a positive result look like?
```
Substrates: Cysteine
Product: Pyruvate, NH3 (ammonia), H2S (hydrogen sulfide)
Reagent/Indicator: Ferric citrate
Media: Peptone iron agar deep
Positive Result: black precipitate
```
51
What organism tested positive in the cysteine desulfhydrase test? Negative?
Positive: Citrobacter freundii
Negative: E. coli
52
What happens if an organism makes cysteine desulfhydrase?
H2S will react with ferric citrate to make ferrous sulfide (FeS) which is black
53
4 biochemical tests used to more precisely identify coliform; used to check quality of water, milk, other foods
IMViC series
54
What does IMViC stand for?
Indole Methyl Red Voges-Proskauer and Citrate test
55
useful in differentiation between several gram negative, enteric bacteria
IMViC
56
determines if organism produce tryptophanase
indole
57
determines if organisms ca ferment glucose by mixed acid fermentation
methyl red
58
determines if organisms can ferment glucose by butanediol fermentation
Vogues-Proskauer
59
determines if organisms can use citrate as a sole carbon source
Citrate
60
What are the substrates, products, reagent/indicator, and media for an indole/tryptophanase test? What does a positive result look like?
```
Substrates: Tryptophan
Products: Indole
Reagent/Indicator: Kovac's reagent
Media: 1% tryptone broth
Positive Result: Red/pink layer on top
```
61
What organism tested positive for an indole test?
Positive: E. coli
Negative: Ent. aerogenes
62
Some organisms use mixed acid fermentation to ferment glucose and produce lots of acid. What is the pH indicator?
Methyl Red
63
What does the MRVP broth contain?
glucose
64
What does the Voges-Proskauer test look for?
Organisms that use butanediol fermentation and produce neutral products such as acetoin from the fermentation of glucose
65
What are the substrates, products, reagent/indicator, and media for a citrate/citrate-permease test? What does a positive result look like?
```
Substrate: Citrate
Product: Alkaline products
Reagent/Indicator: Bromthymol blue
Media: Simmon's citrate agar
Positive: Slant becomes blue
```
66
What organism tested as positive in the MR test? Negative?
Positive: E. coli
Negative: Ent. aerogenes
67
What organism tested as positive in the VP test? Negative?
Positive: Ent. aerogenes
Negative: E. coli
68
What organism tested as positive in the citrate test? Negative?
Positive: Ent. aerogenes
Negative: E. coli
69
What does E. coli reduce to in a nitrate test?
NO2-
70
What does P. denitrificans reduce to in a nitrate test?
N2 or N2O
71
What are the substrates, products, reagent/indicator, and media for a nitrate reductase test? What does a positive result look like?
```
Substrate: Nitrate
Product: Nitrite
Reagent/Indicator: alpha-naphthylamine acetate & sulfanilic acid
Media: Nitrate broth with Durham tube
Positive: Red color
```
72
What are the substrates, products, reagent/indicator, and media for a nitrite reductase test? What does a positive result look like?
```
Substrate: Nitrite
Product: N2O or N2 gas
Reagent/Indicator: Durham tube
Media: Nitrate broth with Durham tube
Positive: bubbles in durham tube
```
73
Purpose of nitrogen fixation lab
to isolate a nitrogen-fixing microbes using an enrichment culture technique
74
What is nitrogen needed for?
nucleic acids, proteins, and some phospholipids
75
Sources of Nitrogen
```
N2 - air
NH3 - ammonia
NO3 - nitrate
NO2 - nitrite
amino acids - organic nitrogen
```
76
the ability of an organism to obtain N2 from the air and covert it to ammonia and organic nitrogen
nitrogen fixation
77
What do organisms use to fix nitrogen?
nitrogenase enzyme complex
78
Dinitrogenase reductase is ____ by oxygen
inhibited
79
aerobic, free-living, nitrogen fixing soil bacterium
azotobacter vinelandii
80
Why does Azotobacter vinelandii use a protein to bind to the nitrogenase complex?
To protect the dinitrogenase reductase from oxygen
81
produces alginate capsule that slows the rate of oxygen absorption
Azotobacter vinelandii
82
breaks down tryptophan into indole, pyretic acid and ammonia
tryptophanase
83
Methyl red turns red below pH
4.2
84
carbon source in a citrate test
sodium citrate
85
nitrogen source in citrate test
ammonium phosphate
86
pH indicator in citrate test
bromythmol blue (green at pH 7, blue above)
87
transports citrate from agar inside the cell to be used as carbon source
citrate permease
88
if an organism can use citrate as a carbon source an ammonium phosphate as a nitrogen source, what will happen to the citrate slant?
organism will grow and produce alkaline product that will turn the slant from green to blue
89
breaks down tryptophan into indole, pyruvic acid and ammonia
tryptophanase
90
beta hemolysis on blood agar
clear colonies, Streptococcus pyogenes
91
alpha hemolysis on blood agar
green colonies
92
structures or substances produced by a microbe which enhance its ability to cause disease
virulence factor
93
What are the substrates, products, reagent/indicator, and media for a coagulase test? What does a positive result look like?
```
Substrate: fibrinogen
Product: fibrin
Reagent/Indicator: Solidification/clots
Media: Plasma
Positive: white solid
```
94
What organism tested positive for coagulase on a MSA plate? Negative?
Positive: Staphylococcus aureus (yellow pigmented)
Negative: Staph epidermis
95
genera that is gram +, catalase +, and salt tolerant
staphylococcus
96
enzyme which converts fibrinogen to fibrin causing plasma to clot; virulence factor
coagulase
97
What is on a Mannitol Salt Agar plate?
7.5% salt
Mannitol - selective for mannitol fermenters
Phenol red - pH indicator
98
How would an organism test positive for coagulase in a plasma tube?
the plasma will clot
99
intimate relationship between 2 dissimilar organisms
symbiosis
100
both organisms benefit fro the relationship (ex. lichens)
mutualism
101
one organism benefits, the other is unaffected (ex. Bacteroides & E. coli)
commensalism
102
both organisms benefit but relationship is not necessary for their survival; each supplies a nutrient required for the other under certain conditions (Ex. lactobacillus & enterococcus can grow without each other on enriched media but can only grow on minimal media if both are present)
synergism
103
host is harmed but parasite benefits (ex. fleas, Bdellovibrio & E. coli)
parasitism
104
one organism produces substance that inhibits another organism (ex. penicillium)
antagonism
105
gram positive, streptobacillus, catalase negative
lactobacillus acidophilus
106
symbiotic relationship with legumes
Rhizobium
107
a protein on the surface of the root hair
lectin
108
a structure formed when Rhizobium bacteria enters the root hair and moves through the root cells
Infection thread
109
an iron containing heme similar to hemoglobin found in plants
leghemoglobin
110
gives the nodule its red or pink color
leghemoglobin
111
restoring soil fertility by providing nitrogen source for the plants; a leguminous crop is substituted for the main cash crop in a field after a certain number of growing season
crop rotation
112
lytic cycle
1. phage attaches to host cell and injects DNA
2. phage DNA circularizes and enters lytic cycle or lysogenic cycle
3. new phage DNA and proteins are synthesized
4. cell lyses, releasing phage virions
113
lysogenic cycle
1. phage attaches to host cell and injects NA
2. phage DNA circularizes and enters lytic cycle or lysogenic cycle
3. phage DNA integrates within the bacterial chromosome by recombination, becoming a prophage
4. Lysogenic bacterium reproduces naturally
5. Occasionally, the prophage may excise from the bacterial chromosome by another recombination event, initiating a lytic cycle
114
chemical that kills or inhibits the growth of mirobes
antimicrobial agent
115
agent that is lethal to microbes
cidal agent
116
agent that inhibits growth and does not kill microbes
static agent
117
antimicrobial agent used only on inanimate objects (ex. ammonia, bleach, ethanol)
disinfectant
118
antimicrobial agent that can be applied to living tissue (ex. iodine, ethanol)
antiseptic
119
Factors affecting the effectiveness of a chemical agent
contact time and concentration of agent
120
effectiveness of an antimicrobial agent is determined by the size of the
zone of inhibition
121
clear area around the anti microbic disc where there is no bacterial growth
zone of inhibition
122
size of the zone of inhibition depends on
1. diffusion rate of the chemical agent into the media
2. concentration of the bacteria
3. type of growth medium
123
chemical substance produced by a microbe that kills or inhibit the growth of other microbes (ex. penicillin)
antibiotic
124
way through which antibodies kill or prevent the growth of pathogens
mode of action
125
What is penicillin's mode of action?
penicillin prevents proper synthesis of the cell wall, subjecting it to lysis
126
smallest amount of agent needed to inhibit the growth of a microbe
Minimum Inhibitory Concentration
127
standard procedure used to measure antimicrobial activity
Kirby Bauer method
128
30S bacterial ribosome inhibitor
Gentamicin or Tetracycline
129
inhibits 50S ribosomal subunit
Chloramphenicol
130
50S bacterial ribosome inhibitor
Erythromycin
131
inhibits transpeptidase, cannot synthesis cell walls
ampicillin
132
interferes with cell wall synthesis
cefoxitin
