Brainscape's Knowledge GenomeTM

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


See full index

Microbiology > Micro-Lab Final > Flashcards

Micro-Lab Final Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Know the steps of the gram stain process

A

…

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

what does a gram negative smear look like (color)?

A

a pink/red color

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

what is an example of a gram negative?

A

escherichia coli

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

what does a gram positive smear look like?

A

purple

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

what is an example of a gram positive bacteria?

A

staphylococcus epidermis

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

what are the differences between gram positive and negative?

A

gram positive has a thick layer of peptidoglycan, while gram negative has a thin outer membrane with over a thin layer of peptidoglycan

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

why do gram positive and negative stain differently?

A

because gram positive doesnt have an outer membrane so the crystal violet is able to penetrate it and stain it but it cant in the gram negative, however safranin does

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

what reagents are used in acid-fast stains

A

kenians reagent

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

why do most stains not work on acid-fast bacteria?

A

because they have a layer of mycolic acid (fatty acid) in the cell wall which makes them waxy and harder for dyes to adhere to

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

know how to explain streaking out a plate

A

…

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

why do we streak out plates?

A

to get isolated colonies

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

what is the purpose of isolating colonies

A

so that the bacteria replicates a new cluster, so we know it is a pure culture

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

what are advantages that capsules give bacteria?

A

better adherence and preventing dying out of the cell

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

why is the acid-fast stain needed?

A

because the fatty acids in the acid-fast bacteria make it very hard for other dyes to adhere to the cell

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

what is an endospore?

A

a structure that bacteria produce to survive harsh conditions, they are tough, dormit and unable to replicate, but they can survive in very harsh climates

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

what does an endospore look like when using the endospore stain?

A

it will appear a greenish blue color due to the malachite green dye used, vegetative cells will appear a red color from the safranin

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

know how to calculate CFUs

A

…

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

facultative anerobe

A

a microbe that can survive both using oxygen and without, however they prefer aerobic conditions

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

aerotolerant

A

microbe that can survive in aerobic conditions but doesnt use the oxygen

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

microaerophile

A

a microbe that uses oxygen but it has to be at lower atmospheric concentrations

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

anerobe

A

a microbe that survives in conditions without oxygen, oxygen is toxic to them

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

halophile

A

microbes that grow in environments that have a high saline concentration

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

halotolerant

A

microbes that tolerate saline conditions but dont prefer them

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

mesophile

A

microbes that prefer moderate temperatures and environments

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

why do a lot of bacteria have a hard time growing in high salt concentrations?

A

because the high salt levels cause osmosis to occur and for water to move out of the cell causing them to die

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

Know how to describe the process and results of a thiglycolate tube and how they are different, and positive and negative results

A

…

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

how did we test for fermentation of lactose? what was used and what were the results?

A

a tube high in lactose and purple in color is inoculated, if the color stayed the same then it was negative but if it turned yellow it was positive due to a pH indicator

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

why was the lactose fermentation tube positive? what did it produce?

A

the products of lactose fermentation were lactic acid and CO2 which would cause the pH to decrease and for the pH indicator to turn yellow

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

what is the mode of action for penicillin?

A

disrupts the peptidoglycan within the cell wall

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

what is the mechanism of action for SXT?

A

kills the bacteria by inhibiting folic acid, which disrupts the DNA synthesis in the cell, halting DNA replication

31
Q

what type of agar plates are used in the Kirby-Bauer test?

A

Mueller-Hinton Agar

32
Q

what do positive and negative results look like in a Kirby-Bauer test?

A

trick question, they are not positive and negative but theu are used to determine how effective antibiotics are on bacteria, ranging from sensitive to resistant to being in the middle

33
Q

what reagent is added to the starch plate to detect the presence of an alpha amylase?

A

iodine

34
Q

what are the two properties of OF tubes that are unique to them? why are they important?

A

a high level of glucose is used to feed the metabolism of bacteria, allowing them to undergo fermentation, the other one is having a very low amount of peptones which makes the environment more alkaline

35
Q

know how the nitrate reductase test is set up, what positive and negative results look like and why zinc is used

A

…

36
Q

why do bacteria secrete exoenzymes?

A

it is energy saving, they break down big macromolecules outside the cell and then bring the subunits inside the cell

37
Q

what is an example of an exoenzyme secreted by bacteria?

A

DNase

38
Q

what does a positive nitrate reductase result look like?

A

pink or red BEFORE the addition of zinc

39
Q

what does a negative result for nitrate reductase look like?

A

tan before the addition of zinc, red/pink after

40
Q

why is Bacillus subtilis able to survive in long exposures to UV light?

A

because they are able to produce endospores

41
Q

why does UV light cause species to die?

A

the UV light causes mutations within the DNA, causes covalent bonds to form between pyrimidines instead of between pyrimidines and purines

42
Q

what is the definition of antiseptic?

A

a chemical compound that controls the bacteria on living tissues

43
Q

what is the definition of disinfectant?

A

a chemical compound that controls bacteria on inanimate surfaces

44
Q

what are aseptic techniques?

A

methods used to prevent contamination of microorganisms

45
Q

know how to determine the thermal death point and thermal death time

A

…

46
Q

what is thermal death time?

A

how long it takes for a bacterium to die at a constant temperature

47
Q

what is thermal death point?

A

the temperature it takes for a bacterium to die at a constant time

48
Q

how does an OF tube work?

A

they are used to determine whether a bacterium undergoes oxidation, fermentation or neither

49
Q

know what positive and negative OF tubes look like

A

…

50
Q

what is a catalase test?

A

a test to determine of the bacteria contains the enzyme catalase to break down hydrogen peroxide

51
Q

what does a positive catalase test look like?

A

there will be bubbles forming when hydrogen peroxide is added to the bacteria

52
Q

what is the enzymatic reaction for the catalase test?

A

H2O2 —> H2O + O2

53
Q

why do bacteria secrete hemolysins?

A

in order to lyse open RBC and break down the hemoglobin within them, they do this to obtain the iron within the heme

54
Q

know why MacConkey agar is both selective and differential and the difference between the two

A

…

55
Q

what does a positive MacConkey Agar look like

A

it turns a bright red/pink

56
Q

what does MacConkey agar test for?

A

lactose fermentation

57
Q

what are the things that KIA tubes can test for?

A

lactose fermentation, glucose fermentation, hydrogen sulfide production, and gas production

58
Q

what does MR assay test for?

A

mixed acid fermentation

59
Q

what reagent is added to MR assay?

A

methyl red

60
Q

what causes the production of indole?

A

the breakdown of Trp

61
Q

know how and why the different results of the KIA test can be seen

A

…

62
Q

what does a positive bile esculin test look like?

A

a dark brown/black color

63
Q

what occurs to make a bile esculin test positive?

A

the breakdown of esculin into glucose, esculetin, and iron is detected

64
Q

what is in CNA blood agar that inhibits Gram negative growth?

A

2 antibiotics, collistin and naladixic acid, these break down gram negative membranes by blocking gyrases and breaking the double strands in the DNA

65
Q

what does a positive urea test look like?

A

bright pink

66
Q

why does the urea test turn color when positive?

A

due to urease producing CO2 and ammonia, which combine with water to make ammonium carbonate which causes the pH to increase and the pH indicator to change to pink

67
Q

what does a positive citrate test look like?

A

it is prussian blue in color, negative remains green/teal

68
Q

how does the citrate assay work?

A

it detects an increase in pH due to the ammonia byproducts forming from a nitrogen source, this is an indirect indicator of the use of carbon sources

69
Q

what is the mechanism of action of novobiocin?

A

the works by inhibiting gyrases

70
Q

what is detected in the VP test?

A

acitoin

71
Q

what does a positive VP test look like?

A

dark red in color

72
Q

what three things does a SIM tube test for?

A

hydrogen sulfide production, indole, and motility

73
Q
A

Microbiology (5 decks)

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