Lab Practical 2 Flashcards
(142 cards)
1
Q
what is the optimum growth temperature?
A
temp where bacteria have the fastest rate of binary fission; where their generation time is the fastest
2
Q
what are mesophiles?
A
optimum growth temp of 20 and 50 degrees
3
Q
what are psychrophiles?
A
bacteria that grow in the range -15 to 20 degrees
4
Q
what are thermophiles?
A
45 to 80 degrees
5
Q
what are hyperthermophiles?
A
67 to 105
6
Q
what is prodigiosin?
A
red pigment protein produced by serratia marcescens
7
Q
In the temperature on bacteria growth lab, what could go wrong?
A
you may have incubated at the wrong temperature
8
Q
what is the optimal growth temperature of s. marcescens?
A
25 degrees
9
Q
what is the optimal growth temp of e coli?
A
37 degrees
10
Q
what is the danger zone of food safety?
A
40 degrees to 140 degrees farenheight
11
Q
what is the peak growth of a pshycrophile?
A
0 degrees celcius
12
Q
what is the peak growth of a thermophile?
A
80 degrees celcius
13
Q
what is osmolarity?
A
a measure of how much solute is dissolved in the solvent
14
Q
what is osmosis?
A
the movement of water into or out of a cell
15
Q
what is an isotonic solution?
A
the concentration of solute inside and outside the cell is equal so there is no movement of water
16
Q
what is a hypotonic solution?
A
the concentration of solute inside the cell is greater than outside the cell so there is a net gain of water for the cell
17
Q
what happens if a cell only has a membrane in an hypotonic solution?
A
bursting
18
Q
How can cells survive in a hypotonic solution?
A
the presence of a cell wall
19
Q
what is a hypertonic solution?
A
there is more solute outside of the cell than inside so water moves outside of the cell.
20
Q
what happens to cells in an hypertonic solution?
A
the cell shrinks
21
Q
why doesn’t a jar of jam in the refrigerator spoil?
A
the concentration of sugar is so high that the solution is hypertonic and the bacteria cannot grow
22
Q
what are halophiles?
A
bacteria capable of growing in high salt concentrations
23
Q
what are osmophiles?
A
bacteria that can tolerate hypertonic solutions (both salt and sugar)
24
Q
where do most halophiles live?
A
the ocean
25
what is the ultraviolet range?
400 and 4 nanometers
26
what is the greatest source of ultraviolet light?
the sun
27
what do pyrimidine dimers do?
cause mutations in the genes in DNA replication sometimes causing cancer
28
What is UV light used to treat?
wastewater, clean room disinfection, air in hospitals
29
what is non-ionizing UV light?
UV light that penetrates surfaces poorly
30
what is ionizing UV light?
UV light that penetrates surfaces
31
what needs to happen for a microorganism to be classified as resistant?
the concentration of a drug required to inhibit or kill the microbe is greater than can safely be achieved in a patient without causing side effects
32
what is the Kirby-Bauer antibiotic sensitivity test?
determines what the best antibiotic and dose to use for a patient
33
What is the accepted standard media used for the Kirby-Bauer?
Muellar-Hinton agar
34
what is the zone of inhibition?
where the antibiotic kills the microbe around the antibiotic disk
35
what are narrow spectrum drugs?
effective against a limited array of different microbes
36
what are broad spectrum drugs?
active against a wider range of different microbes
37
what are some broad spectrum drugs?
tetracycline and ciproflaxin
38
what are some narrow spectrum drugs?
penicillin and vancomycin
39
How can drug resistance be circumvented?
having antibiotics prescribed after a culture and susceptibility test and having patients finish all of their antibiotics
40
what are some good forms of antiseptics?
first aid antiseptic and iodine
41
what disinfectants work the best?
chlorine and lysol
42
if an agent had no effect does that mean that it is an ineffective form of disinfectant?
no because there is probably more bacteria on the media than what the product is normally used to treat
43
how was the disinfectant test biased?
the product must be absorbed into cotton and must be water soluble
44
what is sepsis?
growth of a microorganism in blood and other tissues
45
what is asepsis?
any practice that prevents the entry of infectious agents into sterile tissues to prevent infection
46
what is disinfection?
reducing pathogenic microbes in or on nonliving material to a level where they are no longer a hazard
47
what is sterilization?
removing or killing all the organisms and viruses on an object
48
what is bactericide?
destroys bacteria with the exception of endospores
49
what is fungicide?
destroys fungal spores, hypae and yeast
50
what is virucide?
inactivates viruses
51
what is sporicide?
kills bacterial spores
52
where does most of Houston's drinking water come from?
surface water of the San Jacinto and Trinity rivers
53
what is a coliform?
gram-negative, lactose fermenting bacteria
54
why is e coli a good indicator of fecal contamination?
e. coli is not found in soil so if it is in water it must have come from sewage; it is easily grown outside laboratory conditions; e. coli survives longer outside the body than other organisms
55
what is the presumptive test?
tests for lactose
56
what is the confirmed test?
tests for the presence of gram negative bacteria
57
why are differential and selective agars used for the confirmed test?
they contain chemicals that are toxic to gram positive bacteria
58
what is a completed test?
identifies the species
59
Does a high MPN in the presumptive test mean the water is unsafe to drink?
no, you will not know if coliforms are present until the confirmed test
60
what are some sources of error on the fecal matter test?
not having enough water, contaminating your bottle or pipets, putting wrong amount of water in the test tubes or mislabeling
61
what is an example of a coliform?
e. coli
62
what is an example of a non-coliform?
Pseudomonas aeruginosa
63
what are some prokaryotic pathogens that can be present in sewage water?
e. coli
salmonella
shigella disentarie
vibrio cholera
64
what are some eukaryotic pathogens that can be found in sewage water?
giardia lamblia
entamoeba histolytica
cryptosporidum parvum
65
what are some viral pathogens that can be found in sewage water?
rotavirus, norwalk virus, hepatitis A
66
How can you be certain that your bacteria is e coli during the confirmed test?
because of the colors on the plate,
67
On the Levine EMB agar, what color is a positive result for e coli?
dark black colonies with a green sheen
68
On the endo agar, what color is positive for e coli?
dark red nucleated colonies
69
what is the bacterial count?
the concentration of bacteria present in milk
70
what is pasteurization?
kills certain types of organisms but does not sterilize the product
71
what is the flash method?
71.6 degrees Celsius for 15 seconds
72
why could milk that has always been properly refrigerated have a high bacteria count?
Because the milk has not been properly sterilized and bacteria can still reproduce in refrigeration. Also someone could have drank directly from the container
73
Does the batch or flash method sterilize milk?
no
74
does the ultra high temperature method sterilize milk?
yes
75
why is milk a more suitable vehicle of disease than water?
it carries more nutrients allowing the bacteria to feed more proteins
76
what are some infectious diseases that can be transmitted from cows?
brucella, tuberculosis, listeriosis
77
what are dental caries?
tooth decay
78
why do you form dental caries?
production of lactic acid by bacteria in the presence of high levels of sugar
79
what is a good method to test for tooth decay?
M.L. Snyders caries suseptibility test
80
what indicates the presence of acid production in M. L. Snyder's susceptibility test?
bromcresol green
81
what factors could affect the reliability of M. L. Snyder's test?
not using enough spit, and it is best to do this test a few hours after brushing
82
To increase the validity of M.L. Snyders test, how many times should it be performed?
three times over the course of 72 hours
83
what are some benefits of chewing sugar free gum?
more saliva is produced diluting the acids in your mouth and the stickiness pulls the bacteria from your teeth
83
What is trichinella spirosis?
Cause trichinosis when ingesting raw or undercooked pork.
84
What phylum is trichinosis spiralis?
Nematoda
85
What are the symptoms of trichinosis spiralis?
Nausea, vomiting, abdominal pain, diarrhea, itchy skin, muscle aches, headaches
86
What phylum is enterobius vermicicularis?
Nematoda
87
What is enterobius vermicicularis?
Pinworm. Causes itching around the anus and difficulty sleeping due to the female laying her eggs. Common in children.
88
What is taenia saginata?
Tapeworm. Results from eating undercooked beef.
89
What is the phylum for taenia saginata?
Platyhelminthes
90
What is the class of taenia saginata?
Cestoda
91
What is the head of a tapeworm called?
Scolex
92
What are the individual segments of a tapeworm called?
Proglottids
93
What structures are found on the tapeworm?
Hooks and suckers
94
What are the symptoms of tapeworm?
Abdominal pain, weight loss, proglottids in the feces
95
What is amoeba proteus?
Non pathogenic cousin of enteramoeba histolytica which causes amebiasis.
96
What are the symptoms to amebiasis?
Cramping, pain, dysentery.
97
What are the structures on amoeba proteus?
Pseudopods and nucleus
98
What phylum and class is amoebas proteus
Platyhelminthes Cestoda
99
What is trichomonas vaginalis?
Causes trichomoniasis, a sexually transmitted disease caused by a flagellated protozoan.
100
What are the symptoms of trichomonas vaginalis?
If they occur, inflammation of the mucus membranes of the urethra and vagina. Causes purelent discharge in females and dysuria in males.
101
What are the structures of trichomonas vaginalis?
Nucleus flagella
102
What class and phylum is trichomonas vaginalis in?
Platyhelminthes Cestoda
103
What is trypanosoma Brucei?
Causes sleeping sickness being transmitted by the tsetse fly in rural Africa.
104
What phylum and class does trypanosoma Brucei belong to?
Platyhelminthes Cestoda
105
What are the symptoms of trypanosoma Brucei?
Fever, headaches, muscle pain, extreme fatigue
106
What does trypanosomes Brucei do?
Crosses the blood brain barrier and causes neurological damage.
107
What two species are in the kingdom fungi?
Penicillium rhizopus
108
What are the structures of penicillium?
Conida with spores and mycelium
109
What are the structures of rhizopus??
Mycelium and sporangium with spores.
110
In the Durham test what is a positive result for acid??
Red
111
In the Durham test what is a negative result for acid?
Yellow
112
In the Durham test what is a positive result for co2?
Air bubble
113
In the Durham test what is a negative for co2?
No air bubble
114
What is the indicator of pH in the Durham test?
Phenol red
116
During the methyl red test, what is the results for mixed acid fermentation?
Red is positive
| Yellow is negative.
116
In the urea hydrolysis test, what colors are the result?
Bright pink-- positive for urease
| Orange-- negative for urease
117
What are the results for kligler's iron agar?
Black is positive
| Red, yellow or half and half is negative.
118
What reagent is used for mixed acid fermentation?
Methyl red in the mrvp tube.
119
What are the results in the vogues proskauer test?
Red is postive
| Yellow is negative.
120
What reagent is used for the vogues proskauer test?
Vp-a vp-b
121
What are the results from the tryptone test?
Red oily layer is positive
| Yellow oily layer is negative
122
What reagent is used in the tryptophan test?
Indole
123
What are the results of the Simmons citrate test?
Blue is positive
| Green is negative.
124
What are the results of the phenylalanine test?
Green is positive
| Yellow is negative.
125
What is the reagent used in the phenylalanine test?
Ferric chloride
126
What are the results of the nitrate reduction test?
Red is positive
| Yellow is negative
127
What reagents are used for the nitrate reduction test?
Nitrase a and b
128
What does the durham test test for?
sugars the organism can ferment
129
what does the mixed acid fermentation test for?
mixed acids
130
what does the Vogues-Proskauer test for?
2, 3 butanediol fermentation
131
what does the catalase test for?
catalase
132
what is the reagent for catalase?
hydrogen peroxide
133
what does the citrate utilization test for?
citratase
134
what is metabolism?
all chemical reactions that take place in a cell
135
what is anabolism?
a building up reaction that requires energy
136
what is catabolism?
breakdown of large organic molecules that releases energy
137
what are obligate aerobes?
humans-- must have oxygen to survivve
138
what are obligate anaerobes?
bacteria living deep underground that do not need oxygen to survive
139
what are facultative anaerobes?
can live with or without oxygen
140
what is anaerobic respiration?
most efficient catabolic process for extracting energy from a carbon source
141
what does the nitrate reduction test for?
aerobic respiration
