Lab Flashcards
(102 cards)
1
Q
Ability of lens system to visually enlarge an object
A
Magnification
2
Q
Total magnification
A
Objective lens power x ocular lens power
3
Q
Ocular lens is usually what magnification?
A
10x
4
Q
Objective lenses are typically what magnifications?
A
10,40 or 100x
5
Q
Mathematical function that measures the amount of light gathered from the specimen
A
Numerical apertature
6
Q
The N.A. Of each lens is usually written where?
A
Objective
7
Q
2 N.A. Equals what?
A
N.A. Objective and N.A. Condenser
8
Q
Ability of a lens system to show two adjacent objects as separate and or distinct
A
Resolution
9
Q
When 2 objects appear as 1 what happens?
A
Resolution is lost
10
Q
What are the two things resolution is dependent on?
A
Wavelength of light and numerical aperture
11
Q
This is the limiting property of the lens and is a measure of distance
A
Resolving power
12
Q
The closest two points can be to each other and still appear as distinct objects
A
Resolving power
13
Q
R.P. equals what?
A
Wavelength of light divided by 2 N.A.
14
Q
A shorter wavelength of light results on what?
A
Maximum resolving power
15
Q
Why is resolving power important?
A
If resolving power is not at maximum levels than we would not be able to see the bacteria in any detail bc they are typically 2 micrometers in diameter and 8 micrometers in length
16
Q
What happens when you increases magnification?
A
It causes the light rays to diffract and deflect at the edges in order to trap more light/ direct light into the lens oil used
17
Q
Area visible through the lens
A
Field of view
18
Q
Amount of specimen that is in focus at one time
A
Depth of focus
19
Q
space between the objective lens and the specimen
A
Working distance
20
Q
What decrease as magnification increases?
A
Field of view, depth of focus, and working distance
21
Q
Geographical location where an organism is found
A
Habitat
22
Q
Bacterial types that you expect to find in a particular habitat
A
Normal flora
23
Q
Disease causing organism
A
Pathogen
24
Q
Any unwanted organism
A
Contaminant
25
Aggregation of bacterial cells that occur on an agar surface and is assumed to have come from a since parent cell
Colony
26
Aggregation of cells grown in or on a medium
Culture
27
A mixed culture consists of what?
Two or more cell types
28
A pure culture consists of what?
A single cell type
29
What is the purpose of the aseptic technique?
To prevent contamination of bacterial cultures
30
Gross appearance of a streak
Form
31
Threadlike form with smooth edges
Filiform
32
Threadlike with irregular edges
Echinulate
33
Form that is non to semi confluent
Beased
34
Form that is thin, bead like spreading growth
Effuse
35
Form that is treelike branching
Aborescent
36
Form that is rootlike formation
Rhizoid
37
A dried preparation of cells on a slide
Smear
38
To pass the slide through the Bunson burner
Fix
39
Why do we fix slides?
Cells adhere to the slide, it kills cells pathogenically, and denatures proteins and carmelizes sugars
40
What is the purpose of staining?
Allows cells to be viewed more clearly
41
Single stain that allows observation of morphology and cell arrangement
Simple stain
42
2 or more contrasting stains, allows visualization of specialized structures and separation into groups
Differential
43
Which type of staining stains everything??
Simple stain
44
What are the three most basic dyes?
Methylene blue, crystal violet, and basic fuchsin
45
The three cell shapes are what??
Cocci, rod/bacillus, spirilium
46
What are the 4 arrangements?
Diplo, tetrad, strepto( single chains), and staphylo (clusters)
47
What is the staining technique based on the ability of some cells to resist detaining with alcohol
Gram staining
48
Primary reagent and stain (purple) that colors all cells
Crystal violet
49
A reagent that is a killing agent; substance that increases cells affinity for stains; will intensify color stain.
Fran's iodine
50
Reagent that is a decolorizing agent- lipid solvent- most critical step- may or may not remove primary- based on cell wall composition
95% ethyl alcohol
51
Reagent that is a counterstain( red) and stain is primary washed out by ETOH no CV-1
Safranin
52
What type of procedure involves flaming loop, "grabbing" bacteria with loop, and transfering bacteria onto a slant agar?
subculturing procedure
53
What are the four culture characteristics of an agar slant morphology?
abundance of growth, pigmentation, opitical characteristics, form, and consistency
54
Abundance of growth can be characterized as what?
none, slight, moderate
55
Pigmentation can be described as what?
color-pure white, dirty white, yellowish, ect.
56
Optical characteristics can be defined as what?
how much light passes through the colonies- transparent (full trans.) or translucent (partial transmission)
57
To check the bacteria`s consistency, what should one do?
flame loop, cool, touch to colony
58
Consistency can be described as what?
sticky, moist, slimy, dry, no moisture, or flaky
59
The shape and arrangement of bacterium
morphology
60
What problem can occur when performing a negative stain?
If you add too much stain light will not pass through and the same is true if you do not add enough
61
What is a negative stain also called and why?
A background stain because the slide is colored black and the specimen will be clear
62
What type of dye is the negative stain and what does this mean?
It is an acidic dye meaning that it will not enter the cell or bind to it
63
In a negative stain what charge are the bacteria and the dye used?
negative and they dye is Nigrosine dye
64
What is the only stain that you will perform without a smear and does not require a heat fix?
negative stain
65
In a gram stain, if the results are purple/bluish what does that mean?
That the results are gram + and they retained the CV-1
66
In a gram stain, if the results are pink/reddish what does that mean?
The results are gram - and the CV-1 washed out
67
What is the purpose of the gram stain?
To look at the composition of the cell wall, mainly the peptidoglycan layer
68
Who developed the acid fast stain?
Paul Ehrlich
69
The RESISTANCE of certain cells that have been stained with basic dye to decolorize in the presence of acidified alcohol.
acid fastness
70
What is the most important property of the acid fast stain?
Differentiating the genus Mycobacterium (leprae & tuberculosis) which can be pathogenic
71
What are some characteristics of the acid fast stain?
Mycobacterium, thick/waxy cell wall, doesn`t stain well with M. blue or CV-1, uses Carbol Fuchsin in 5% phenol that is soluble/retained in the waxy wall
72
What are the reagents in the acid fast stain?
Acid-Alcohol (3% HCl & 95% ETOH), Carbol Fuchsin, and Methylene blue
73
What are some things to remember for the acid fast stain?
requires intact cells, works best with older cells, and unknown is acid fast negative
74
What do acid fast cells do?
retain carbol fushin and are red (pink) rods
75
What do non acid fast cells do?
They will be destained with the acid alcohol and counterstain with methylene blue so they will be blue cocci
76
What will tissues such as lung and epithelial tissue do in an acid fast stain?
stain blue
77
What structures are highly resistant and are thick walled?
endospores
78
Vegetative cells will go through a process called what? when stressed from environmental factors.
sporogenesis
79
An endospore is made with impervious layers called what?
spore coats
80
As the environment worsens that endospore is released as is called a what?
free spore
81
When the environment is favorable, the free spore will germinate into a what?
vegetative cell
82
Metabolically inactive cells
spore
83
Endospores belong mainly to the genera of what?
Bacillus and Clostridium (gram + rods)
84
What is the primary stain in the endospore stain?
Malachite Green
85
What does the Malachite Green stain do?
It will penetrate the vegetative cell and the endospore will heat
86
What is the decolorizing agent in an endospore stain?
water
87
What does water do in an endospore stain?
it dilutes the stain throughout the cell except with the endospore
88
What is the counterstain in an endospore stain?
Safranin
89
What does Safranin do in an endospore stain?
it stains the vegetative cell structures
90
If the bacteria has this then they will move through a semi-hard substance such as an agar.
flagella
91
Increasing temperature will denaturize proteins true or false?
true
92
Decreasing temperature decreases what two things?
enzyme activity and cellular metabolism
93
-5 to 20* C
Psychrophiles
94
20-45*C
Mesophiles (most common)
95
35*C and up
Thermophiles
96
Thermophiles that are 45-60*C
facultative
97
Thermophiles that are only above 50*C
obligate
98
What are the toxic metabolic end products of cellular respiration?
free radicals, hydrogen peroxide, and superoxides
99
Media that suppresses the growth of unwanted microbes and encourages the growth of desirable microbes with the use of selective agents.
selective media
100
What can selective agents be? (3 types)
antibiotics, chemicals (NaCl) or dyes (MB or CV)
101
Selective media is used for the isolation of pathogentic staphlococci: true or false?
true
102
Media designated to distinguish between species or groups of microbes, includes a substance that is altered or utilized by some organisms but not others, and causes visible change in the colony or the media
differential media
