Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology > Lab Exam 2 Test Questions > Flashcards

Lab Exam 2 Test Questions Flashcards

1
Q

What is the purpose of Hemolysis?

A

To see what type of hemolysis a bacteria can conduct: alpha, beta, and gamma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the procedure of Hemolysis?

A

Do a streak for isolation on the plate. After incubation read for hemolysis and compare with the controls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the reagents involved in Hemolysis?

A

Blood Agar Plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does a positive look like in Hemolysis?

A

Beta → Clearing & Alpha → Green

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does the positive mean in Hemolysis?

A

Beta means the bacteria lyse cells completely; alpha means lysts cells partially

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does a negative look like in Hemolysis?

A

Gamma → No Hemolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Does Hemolysis utilize a pH indicator?

A

NO!!!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the purpose of Thioglycate?

A

To see what kind of oxygen requirements the bacteria has: obligate aerobe OR facultative anaerobe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the procedure for Thioglycate?

A

Innoculate your bacteria into a broth of thioglycolate and resazurin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the reagents involved in Thioglycate? (and what do they do)

A

Thioglycolate removes oxygen from the media, and resazurin indicates the presence of oxygen (OXYGEN INDICATOR)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does a positive result look like for Thioglycate?

A

Obligate Aerobe = growth only at the top (needs oxygen) & Facultative Aanerobe = growth throughout (does NOT need oxygen)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is an important aspect of Thioglycate?

A

Do NOT shake as it will introduce unwanted oxygen to occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the purpose of Motility?

A

To see if bacteria have flagella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the procedure for Motility?

A

Stab semi-solid auger w/TTC with bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the reagents involved in Motility and what do they do?

A

Semi-sold auger w/TTC = TTC turns a red color and acts as a way to see if bacteria will have flagella, it will turn red to show movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does a positive result look like for Motility?

A

Red away from the stab line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does a positive result mean for Motility?

A

Bacteria HAS flagella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does a negative result in Motility look like?

A

Red ONLY at the stab line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the purpose of Simmon’s Citrate?

A

To see if bacteria can use citrate as a carbon source

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the procedure for Simmon’s Citrate?

A

Innoculate the citrate slant with your organism. Incubate at optimum temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the reagents involved in Simmon’s Citrate?

A

TSA slant sodium citrate, bromothymol blue (pH Indicator, In Media)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does a positive result look like for Simmon’s Citrate?

A

TSA slant turns blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does a positive result mean for Simmon’s Citrate?

A

The bacteria CAN use citrate as a carbon source

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does a negative result look like in Simmon’s Citrate?

A

TSA slant stays green

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Does Simmon’s Citrate utilize a pH indicator?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the pH indicator used in Simmon’s Citrate?

A

Bromothymol Blue (in media)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the purpose of Gram’s Stain?

A

To see cell shape and to figure out if it is Gram-Positive or Gram-Negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the reagents utilized in Gram’s Stain?

A

Crystal Violet, Iodine, Ethanol, and Safranin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What does a positive result look like in Gram’s Stain?

A

Purple/Violet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What does a positive result mean in Gram’s Stain?

A

The bacteria have peptidoglycan on the outside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What does a negative result look like in Gram’s Stain?

A

Pink/Fuschia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the purpose of Catalase?

A

To see if bacteria have the catalase enzyme. The enzyme degrades hydrogen peroxide to produce oxygen and water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the procedure for Catalase?

A

Add a drop of hydrogen peroxide to the TSA plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are the reagents utilized in Catalase?

A

TSA Plate & Hydrogen Peroxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What does a positive result look like in Catalase?

A

Gas Bubbles are present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What does a positive result mean in Catalase?

A

The bacteria have catalase, and gas bubbles mean that there is oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What does a negative result look like in Catalase?

A

No gas bubbles are present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is the purpose of the Spirit Blue Plate?

A

To see if bacteria can produce lipase - which breaks lipids apart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the procedure for the Spirit Blue Plate?

A

Innoculate the spirit blue plate with a streak in the center with your organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What are the reagents involved in the Spirit Blue Plate?

A

Tributryin Oil & Spirit Blue (pH Indicator)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What does a positive result look like for the Spirit Blue Plate?

A

Dark blue precipitate around bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What does a positive result mean for the Spirit Blue Plate?

A

Bacteria can produce lipase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What does a negative result look like for the Spirit Blue Plate?

A

No halo or plate is grey

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the purpose of the Capsule Stain?

A

To see if bacteria have a capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What are the reagents involved in Capsule Stain?

A

Congo Red & Maneval’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What does a positive result look like in a Capsule Stain?

A

Halo around bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What does a positive result mean in a Capsule Stain?

A

Halo means that the bacteria has a capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What does a negative result look like in a Capsule Stain?

A

No halo is present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What is the purpose of SIM-Sulfur?

A

To reduce sulfur and use cystine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What is the procedure for SIM-Sulfur?

A

Inoculate the SIM agar with your organism. Incubate at your optimum temperature.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What are the reagents utilized in SIM-Sulfur?

A

Iron Salts & Cystine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What does a positive result look like in SIM-Sulfur?

A

Black

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What does a positive result mean in SIM-Sulfur?

A

Black precipitate indicates that there is a sulfur reaction (H2S + iron salt)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What does a negative result look like in SIM-Sulfur?

A

Yellow/No color change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is the purpose of SIM-Indole?

A

To see if tryptophan can be turned into indole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is the procedure for SIM-Indole?

A

Inoculate the SIM agar with your organism. Incubate at your optimum temperature. After incubation add 10 drops of Kovac’s reagent to the tube. Compare your results to the positive control.

57
Q

What are the reagents utilized in SIM-Indole?

A

Kovac’s Reagent & Tryptophan

58
Q

What does a positive result look like in SIM-Indole?

A

Red at the top of the tube

59
Q

What does a positive result mean in SIM-Indole?

A

Red means that there is indole present

60
Q

What does a negative result look like in SIM-Indole?

A

Yellow/No color change

61
Q

What is the purpose of Voges Proskauer?

A

To see if bacteria can make acetoin which is turned into butanediol

62
Q

What is the procedure for Voges Proskauer?

A

Inoculate an MR-VP broth with your organism. Incubate at your optimum temperature. After incubation add 10 drops of VP A (α -Naphthol) and 8 drops of VP B (Potassium hydroxide) to the tube. Shake well to aerate the tube. Let sit for 15 minutes before reading the results

63
Q

What does a positive result look like in Voges Proskauer?

A

Brick Red

64
Q

What does a positive result mean in Voges Proskauer?

A

Red means the presence of acetoin which will become butanediol

65
Q

What does a negative result look like in Voges Proskauer?

A

No color change

66
Q

What is an important aspect of Voges Proskauer?

A

Make sure that the order or adding reagents is IMPORTANT!
–> VPA THEN VPB

67
Q

What are the reagents utilized in Voges Proskauer?

A

Alpha-Naphthol (VPA) & Potassium Hydroxide (KOH) (VPB)

68
Q

What is the purpose of DNAse?

A

To see if bacteria can make the enzyme DNAse, which breaks down DNA

69
Q

What is the procedure for DNAse?

A

Inoculate the DNase plate with your organism. Incubate at your optimum temperature. After incubation compare your plate to the positive control. You should notice a clearing around the margins of growth if your organism is positive for DNase production

70
Q

What are reagents involved in DNAse?

A

DNA & Methyl Green

71
Q

What does a positive result look like in DNAse?

A

Halo around bacteria

72
Q

What does a positive result mean in DNAse?

A

Halo means that bacteria have DNAse which destroys DNA

73
Q

What does a negative result look like in DNAse?

A

No halo around the bacteria

74
Q

What is the purpose of the Milk Plate?

A

To see if bacteria make caseinase, which breaks down casein, a protein in milk

75
Q

What is the procedure for the Milk Plate?

A

Inoculate the skim milk plate with a streak in the center with your organism. Incubate at your optimum temperature for 5 days

76
Q

What are the reagents involved in the Milk Plate?

A

Milk in plate

77
Q

What does a positive result look like in the Milk Plate?

A

Halo around bacteria

78
Q

What does the positive result mean in the Milk Plate?

A

Halo means that bacteria have caseinase, which destroys casein in milk

79
Q

What does a negative result mean in the Milk Plate?

A

No halo around the bacteria

80
Q

What is the purpose of the Starch Plate?

A

To see if bacteria make amylase, which breaks down starch into glucose

81
Q

What is the procedure for the Starch Plate?

A

Inoculate the starch plate with a heavy streak in the center of the plate with your organism. Incubate at your optimum temperature for 5 days. After incubation flood the plate with Gram’s iodine and read the results right away. Be careful not to tip the plate or the liquid will pour out.

82
Q

What are the reagents involved in the Starch Plate?

A

Iodine & Starch

83
Q

What does a positive result look like in the Starch Plate?

A

Halo around bacteria, with black around the halo

84
Q

What does the positive result mean in the Starch Plate?

A

Halo around bacteria means bacteria makes amylase, which destroys starch into glucose (iodine only binds to starch, glucose does not bind to iodine)

85
Q

What does a negative result look like in the Starch Plate?

A

No halo around the bacteria

86
Q

What is the purpose of the Phenylalanine Slant?

A

To see if bacteria will make phenylalanine deaminase, which releases NH3

87
Q

What is the procedure for the Phenylalanine Slant?

A

Inoculate the phenylalanine slant (this slant looks a lot like a TSA slant) with your organism. Incubate it at your optimum temperature. After incubation add four drops of 10% ferric chloride to the slant. Compare your results to the positive control. A green color should appear if your tube is positive. If it stays yellow, then it is negative.

88
Q

What are the reagents utilized in the Phenylalanine Slant?

A

10% Ferric Chloride & Phenylalanine

89
Q

What does a positive result look like in the Phenylalanine Slant?

A

Green

90
Q

What does the positive result mean in the Phenylalanine Slant?

A

Greens mean that bacteria can turn phenylalanine into NH3

91
Q

What does the negative result mean in the Phenylalanine Slant?

A

No color change

92
Q

What is the purpose of OF Glucose?

A

the ability of bacteria to oxidize or ferment a specific carbohydrate

93
Q

What is the procedure for OF Glucose?

A

Inoculate two tubes of O-F glucose media with your organism. Overlay one tube with oil. Do Not forget this step otherwise, you will have to redo the test. Incubate these tubes in a rack labeled fermentation at your optimum temperature. At your 24-hour reading note the color change of both tubes. Place back in the rack for Reincubation. At your 48-hour reading during your class period note the color change of both tubes. Compare your tubes to the Fermentative control and the oxidative control

94
Q

What are the reagents utilized in OF Glucose?

A

Bromothymol blue, mineral oil, glucose

95
Q

What does a positive result look like in OF Glucose?

A

3 categories: both green=negative, both yellow=fermentation, one green one yellow=oxidation

96
Q

What does a negative result look like in OF Glucose?

A

Both green

97
Q

What is the purpose of the Gelatin Stab?

A

To see if bacteria makes gelatinase, which breaks gelatin down

98
Q

What is the procedure for the Gelatin Stab?

A

Inoculate the gelatin stab with your organism. Incubate at your optimum temperature for 5 days. After incubation, your instructor will ask for your gelatin tubes if they are liquid. These will be placed in a rack and moved to the refrigerator for 15 minutes. If the gelatin in your tube is solid you do not need to refrigerate it, and this is a negative result. Once the 15 minutes is up obtain your tube right away to read it otherwise if it is solid it might liquefy due to the room temperature

99
Q

What are the reagents utilized in the Gelatin Stab?

A

Semi-solid auger with gelatin

100
Q

What does a positive result look like in the Gelatin Stab?

A

Liquid if it stays that way after 15 minutes in the fridge

101
Q

What does the positive result mean in the Gelatin Stab?

A

Liquid if it has gelatinase, which breaks down gelatin

102
Q

What does the negative result look like for the Gelatin Stab?

A

It is SOLID

103
Q

What is the purpose of the Methyl Red Test?

A

To see if bacteria can make mixed acids with fermentation

104
Q

What is the procedure for the Methyl Red Test?

A

Inoculate an MR-VP broth with your organism. Incubate at your optimum temperature for five days. After incubation add 5 drops of methyl red. Mix and compare your results with the positive and negative controls. Record if yours is negative or positive.

105
Q

What are the reagents utilized in the Methyl Red Test?

A

Methyl Red

106
Q

What does the positive result look like in the Methyl Red Test?

A

Red

107
Q

What does the positive result mean in the Methyl Red Test?

A

Red means the bacteria makes mixed acids through fermentation

108
Q

What does the negative result look like in the Methyl Red Test?

A

Yellow/No Change

109
Q

What is the purpose of Nitrate Reduction?

A

To see if the bacteria makes nitrate reductase enzyme which turns NO3 (nitrate) into NO2 (nitrite)

110
Q

What is the procedure for Nitrate Reduction?

A

Inoculate the nitrate broth with your organism. Incubate at your optimum temperature. After incubation add 5 drops of Reagent A and 5 drops of Reagent B to the tube. The mix will note any color change. If your tube turned red you are done, and this is a positive result. If there was no color change add a small amount of Reagent C. Mix well and note any color change. If your tube turned red you are done, and this is a negative result. However, if there was no color change you are done, and this is a positive result. Compare your result to the controls. The positive control is after the addition of Reagent A and Reagent B. The negative control is after the addition of Reagent A, Reagent B, and Reagent C

111
Q

What are the reagents utilized in Nitrate Reduction?

A

Dimethyl-alpha-napthalamine (reagent A), then sulfanilic acid (reagent B); maybe zinc (reagent C)

112
Q

What does a positive result look like in Nitrate Reduction?

A

A + B = Red, A + B + C = Clear

113
Q

What does the positive result mean in Nitrate Reduction?

A

If A + B = red means NO3 to NO2, or if A + B + C = clear then NO3 to NO2 to N2 gas, so both have nitrate reductase

114
Q

What does a negative result look like in Nitrate Reduction?

A

A + B + C = Red

115
Q

What is the purpose of the Fermentation Tubes?

A

To see if bacteria can ferment different types of sugars

116
Q

What is the procedure for the Fermentation Tubes?

A

Inoculate the six fermentation broths with your organism. Since these broths are all the same color it is recommended that you take a marker with you and label each tube as you obtain them. Incubate these tubes in the rack labeled for fermentation at your optimum temperature as you will have to read them at 24 hours and 48 hours

117
Q

What are the reagents utilized in the Fermentation Tubes?

A

sucrose, lactose, maltose, glucose, trehalose, phenol red, peptone

118
Q

What does a positive result look like in the Fermentation Tubes?

A

Yellow and maybe gas

119
Q

What does a positive result mean in the Fermentation Tubes?

A

Yellow (and maybe gas) means it can ferment that sugar

120
Q

What does a negative result mean in the Fermentation Tubes?

A

Pink/Red

121
Q

What is an important thing to note for the Fermentation Tubes?

A

DURHAM MUST HAVE 10% OR MORE TO COUNT AS GAS

122
Q

What is the purpose of the Urease test?

A

To see if bacteria can make urease

123
Q

What is the procedure for the Urease test?

A

Inoculate the urea broth with your organism. Incubate at your optimum temperature for 5 days. After incubation compare your results to the control and the uninoculated control. If your urea broth is positive it should be pink

124
Q

What are the reagents utilized in the Urease test?

A

Urea & Phenol Red

125
Q

What does a positive result look like in the Urease test?

A

Fuschia Pink (Bright Pink)

126
Q

What does the positive result mean in the Urease test?

A

Pink means it makes urease (Urea > NH3, which is basic)

127
Q

What does a negative result look like in the Urease test?

A

Yellow or Gray (No Change)

128
Q

What is the purpose of Decarboxylation?

A

To see if bacteria can produce decarboxylases by removing the carboxyl group from amino acids

129
Q

What is the procedure for Decarboxylation?

A

Inoculate all three decarboxylation broths (these all are the same color) with your organism. Overlay all tubes with oil. Remember this step otherwise you cannot read your results. Incubate at your optimum temperature. After incubation make sure there is oil on the top of the broth before doing your result reading. Compare your tubes to the positive control, and the two negative controls

130
Q

What does a positive result look like for Decarboxylation?

A

Purple

131
Q

What are the reagents utilized in Decarboxylation?

A

peptone, glucose, bromocresol purple, pyridoxal phosphate, and either lysine, arginine, or ornithine

132
Q

What does the positive result mean for Decarboxylation?

A

Purple means bacteria produce decarboxylase for that amino acid

133
Q

What does a negative result look like in Decarboxylation?

A

Yellow or Gray (NO change)

134
Q

What is the pH indicator utilized in Decarboxylation?

A

Bromocrescol Purple (in media)

135
Q

What is the pH indicator utilized in Simmon’s Citrate?

A

Bromothymol Blue (in media)

136
Q

What is the pH indicator utilized in the Methyl Red test?

A

Methyl Red (added)

137
Q

What is the pH indicator PHENOL RED utilized in?

A

Fermentation Tubes (it is already inside the media)

138
Q

What is the pH indicator SPIRIT BLUE utilized in?

A

Spirit Blue Plate (in media)

Microbiology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions