Micro Midterm Lab Practical Flashcards

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0
Q
Where do you dispose...
Used glass test tubes 
Used glass slides
Broken glass
Used latex gloves
Paper towels used in bench disinfection
Uncontaminated trash
 Contaminated Petri plates 
Qtip swabs used to clean microscopes
A
Discard racks
Disinfectant basin
Cardboard broken glass receptacle
Autoclave trash
Regular trash
Regular trash
Autoclave trash
Regular trash
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1
Q

Function of ocular

A

The eye piece that Magnifies an image ten times

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2
Q

Function of objective lenses

A

Magnify an image at varying amounts

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3
Q

Function Of Condenser

A

Concentrates the light beam onto the specimen

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4
Q

Function of the course focus knob

A

Refine resolution of images on a larger scale

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5
Q

Function of iris diaphragm lever

A

Enlarges the iris diaphragm to let increase light intensity

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6
Q

Function of mechanical stage knobs

A

Allows you to move the specimen around to find things

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7
Q

Function oF Condenser height adjustment knobs

A

Adjust. Height of condenser

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8
Q

Function of condenser centering screws

A

Centers the condenser

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9
Q

Function of diopter ring

A

Allows you to focus the individual eyepiece To your eye.

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10
Q

Function of base diaphragm

A

H

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11
Q

Function of fine focus knob

A

Adjust the resolution at a smaller scale

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12
Q

Function of stage clip

A

Hold slide. In. Place

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13
Q

Describe the steps to cleaning. A microscope properly

A
  1. Rotate nosepiece to 5xs objective
  2. Remove excess. Oil from oil immersion objective with qtip
  3. Clean all lenses with lens cleaner and qtips and dry
  4. Turn down rheostat and turn off light switch
  5. Replace cover
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14
Q

Explain. Purpose of using immersion oil who using 100x objective

A

It minimizes the amount of light that is refracted or lost and therefore. Increases resolution of the image.

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15
Q

Name two major types of microscopes that have been developed and. And name the difference between. These two types. Of microscopes

A

Compound microscope- uses light

Electron microscopes- uses electrons to produce. Image

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16
Q

List 4 examples. Of compound microscopes and star the example you will use in lab

A

Phase contrast
*bright field
Dark
Fluorescent

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17
Q

Define magnification

A

Ability of. Microscope to enlarge an object

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18
Q

Name two magnifying lenses. In a compound microscope

A

Objective lens

Ocular/eyepiece lens

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19
Q

List. Common names. And the magnification of the four objectives you will. Use in this. Lab

A

Scanning. Objective- 4x
Lower power objective- 10x
High power. Objective- 40
Oil immersion objective-100x

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20
Q

How is total magnification of an object calculated?

A

Ocular x objective = total magnification

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21
Q

State the. Two. Factors that. Determine. How we’ll an object. Can e seen with a. Microscope

A

Resolution and magnification

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22
Q

Define. Resolution

A

Describes. How clear specimen will appear when viewed through the lenses

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23
Q

Name the. Two components that influence the resolving. Power of. A microscope

A

Numerical aperture and. Wavelength of light

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24
Q

Define refractive index

A

Measures. How. Lens. Is. Able to bend light

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25
Q

Function off iris diaphragm

A

Regulates intensity of light entering. Lenses

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26
Q

State three steps to achieve adequate lighting when the. Oil immersion objective is. Used to. View a specimen

A
  1. Condenser raised to highest. Opposition
  2. Iris and bars diaphragm are all the way open
  3. Rheostat turned ups s much as I can stand it.
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27
Q

Define ubiquitous

A

They are everywhere

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28
Q

Define pure culture

A

Isolation of a single strain of bacteria

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29
Q

Define colony

A

A group. Of bacteria that descend from a single. Parent that reproduced asexually and are identical. To each other

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30
Q

Define. Turbidity

A

Cloudiness that indicates growth

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31
Q

Define media

A

Nutrient material. Suitable for cultivation of micro organisms.

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32
Q

Define inoculum

A

Transfer a sampling of umpire culture

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33
Q

Define aseptic technique

A

Techniques developed to prevent contaminating microbes from entering cultures.

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34
Q

Why is it important to allow the loop. To. Cool before obtaining your bacterial sample?

A

If we used a hot loop, we would kill the bacteria we are. Trying to transfer

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35
Q

Why is it. Important. To hold the test tube cap with your little finger while taking your bacterial sample?

A

To prevent contamination

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36
Q

Why is. It important. To. Obtain a pinpoint amount. Of sample as. Your inoculum?

A

So ewe don’t get to much so the bacteria can stain and Decolorize properly

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37
Q

Why are. The agar plates labeled on the bottom?

Why are they inverted when incubated?

A

So we can see the writing, and it stays I with the agar, and. Des not move when the lid is turned.
To prevent condensation onthe media

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38
Q

What is the. Criteria used to describe a bacterial colony?

A

The shape, margin (edge), elevation, texture, and pigment

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39
Q

State three ways that lab Media. CAn become Contaminated AND give specific. Aseptic techniques that can be used to. Prevent that type of. Contamination.

A

A. Surface of skin- wear gloves and wash hands
B. unsterile equipment- sufficiently sterilized don’t use used stuff
C. Exposing. Media to contaminated air- put cap back on ASAP, hold lid with little. Finger.

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40
Q

Describe the. Steps involved. In labeling a test tube

A

Get labeling tape write initials. Ont it and stick it onthe. Tube

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41
Q

Describe all steps involved in labeling a Petri plate

A

Label he bottom with name or. Initials

NEVER ON THE LID

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42
Q

Describe all steps involved in incubating a Petri plate

A

Stack agar plate lid side down so condensation forms on the lid not on the he media where bacteria grow.

43
Q

List in order the reagents used in the traditional gram stain procedure

A

Crystal violet
Iodine
Acetone alcohol
Safranin

44
Q

State the function of a each reagent

A

Crystal violet- primary dye, stains all the he bacteria on the slide
Iodine- mordant, binds with crystal bviolet and makes large molecules that get stuck under gram positives large cell wall
Acid alcohol-decolorizes those bacterial that don’t have large walls
Safranin-secondary dye, stains all remaining bacteria

45
Q

Explain the mechanism of the grams stain (why gram negative cells lose the primary dye during decolorization)

A

The decolorizer breaks up the lipids of membranes, gram negative cells have an outer membrane and then the dye is released.

46
Q

What color are gram positive and gram negative cells? What are there two shapes?

A

Gram positive are purple
Gram negative are pink
Cocci-round
Bacilli-rod

47
Q

Explain the difference between a simple stain and a differential stain

A

Simple only uses one dye, and tells us shape size configuration
Differential stain uses two dyes and tells us all that plus something else

48
Q

Why are basic dyes used in the he gram stain?

A

They have an overall positive charge which is attracted to the negatively charged bacteria

49
Q

Explain the difference between the cell wall composition of gram negative bacteria and gram positive bacteria.

A

Gram positive have a large layer of peptidoglycan

Gran negative bacteria have an outer cell membrane with a thin layer of peptidoglycan underneath.

50
Q

What is the importance of allowing the smear to air dry?

A

So get he cell walk doesn’t burst due to boiling insides and they stay intact

51
Q

What is the importance of decolorizing the smears one at a time?

A

Most critical and difficult step, no set time for it so you have to be careful and watch carefully

52
Q

State the two genera that are idtified using the acid fast stain. State diseases caused by acid fast bacteria

A

Mycobacterium- tuberculosis and leprosy

Nocardia- nocardiosis and cryptosporidiosis (diarrheal disease)

53
Q

What color are acid fast organisms and non acid fast organisms

A

Acid fast are pink

Non acid fast are blue

54
Q

Explain why certain organisms are acid fast

A

Acid fasts organisms have really waxy walls that prevent decolorization

55
Q

Differentiate between the decolorizer used in he the acid fast stain and the gram stain.

A

Gram-acetone alcohol

Acid fast- acid alcohol

56
Q

State, in order, the three reagents used in the acid fast stain.

A

Carbolfuchsin
Acid alcohol
Methylene blue

57
Q

Why is the acid fast stain considered differential stain

A

There are two stains or dyes. Used

Distinguishes 2 groups of organisms tells more than just size shape and arrangement

58
Q

What is the difference between the Ziehl-Neelsen stain and the kinyoun stain?

A

Zn uses steam to penetrate my colic acid

K uses very cone rotated dye, hard heat fixing and longer exposure tim.

59
Q

Name two medically important genera of bacteria that produce endospores

A

Bacillus and clostridium

60
Q

What color are the vegetative cell ands endospore

A

Endospore is green

Vegetative cell is red

61
Q

Describe the process paused to stain the relatively impermeable endospores

A

Heat and extended stain time

62
Q

Name the dyes used in huge schaeffer-Fulton spore stain

A

Malachite green

Safranin

63
Q

Define vegetative cell

A

Metabolically active, replicating cell

64
Q

Define sporogenesis

A

Formation. Of endoscopes

65
Q

Define germination

A

Reverting from endospore to vegetative cell

66
Q

Why are endospores considered he most resistant life form known?

A

Can remain dormant indefinitely

Resistant to antibiotics, most disinfectants, radiation, boiling, and drying

67
Q

List five medically important endoscope producing bacteria and their associated disease

A
  1. Bacillus anthracis-anthrax
  2. Clostridium botulinum- botulism
  3. Clostridium difficile- toxic enterocolitis
  4. Clostridium perfringens- gangrene/food poisoning
  5. Clostridium tetani- tetanus
68
Q

What is the difference. greens positive stain and a negative stain?

A

Negative- stains everything except what we want to see

Positive- stains object we want to see

69
Q

What does a bacterial capsule look like in a negative stain?

A

White halo

70
Q

Using Anthony’s stain, the background will be colored ? And the capsule will be colored ?

A

Dark blue and light blue/white

71
Q

State two advantages of using a negative stain versus a positive stain.

A
  1. See he microorganism alive, don’t have to heat fix it

2. Can see things you wouldn’t with a + dye

72
Q

Explain why nigrosin and India ink are commonly used in negative stains

A

Hey are acidic (negatively charged) and are repelled by the negative charged contents if cell wall

73
Q

Differentiate between a capsule and a slime layer

A

Capsule- firmly attached to cell all, firm in shape

Slime- loosely attached, irregularly shaped

74
Q

State. Three ways a capsule contributes to the virulence of a bacteria

A
  1. Sticky so attatchment to skin and mucous membranes
  2. Sourced of nutrition
  3. Helps avoid phagocytosis
75
Q

State two differences between the smear preparation for a gram stain and a capsule stain

A

No heat

No rinse with water

76
Q

Define reducing agent

A

Binds to oxygen and turns it into water

77
Q

Why is thioglycollate a semi-solid agar?

A

Contains solid agar but because of water produced by reducing agents, it becomes more liquified

78
Q

What are the damaging by products of oxygen during cellular respiration?

A

Superoxides and peroxides

79
Q

Name three enzymes that neutralize the damaging effects of suoeroxides and peroxides

A

Catalase, perixidase, and superoxidase dismutase

80
Q

What is the difference between an aerobe and an anaerobes?

A

Aerobes have enzymes that break down toxic forms of oxygen and their intermediate by products, they use oxygen as the final member of the etc
Anaerobes have no tolerance for oxygen cuz have no enzymes to break down oxygen byproducts, Don’t use oxygen as final member of etc

81
Q

How does the candle jar achieve an atmosphere to grow microaerophilic, capnophilic organisms

A

A flame is lit which consumes oxygen and produces carbon dioxide

82
Q

How does the gas pack jar achieve an anaerobic atmosphere?

A

Hydrogen gas is real eased whew aged and palladium catalyst are in the lid, hydrogen combines with oxygen and turns to water.

83
Q

Which type or organism grows equally well in all types of oxygen concentrations?

A

facultative anaerobes

84
Q

How does the thioglycollate both grow anaerobic bacteria as well as aerobic bacteria?

A

It contains a small amount of agar which helps retard oxygen diffusion. So oxygen can’t get through alo of it, so oxygen at the top, not oxygen at the bottom

85
Q

What organisms can have any manhunt of oxygen present?

A

Facultative anaerobe

86
Q

What organism require 20% oxygen?

A

Obligate aerobes

87
Q

What organisms can not have any oxygen present?

A

Obligate anaerobes

88
Q

Which organisms like co2

Which ones like a lower percent of o2?

A

Capnophile

Microaerophile

89
Q

Describe the genes located onthe. Pglo plasmid

A

Ara-c- produces a represent protein
GFP- produces the protein that allows it to glow
BLA- produces the antibiotic resistant protein

90
Q

Describe the protein encoded in the pglo series

A

Ara-c repressor protein
Green fluorescent protein
Beta lactamase

91
Q

Define competent and describe two methods to make e. Coli competent

A

Able to take up DNA from an environment!

  1. Growth in presence if calcium chloride
  2. Extreme temperature changes
92
Q

Explain the regulation mechanism of the green fluorescent protein gene expression

A

Ara-c repressor protein blocks transcription and translation of GFP
Arabinose moves Ara-c out of the way

93
Q

Which gene allows jellyfish to glow in the dark?

A

GFP

94
Q

What is the relationship between a gene and a protein?

A

A gene is a piece of DNA that codes for making a protein

95
Q

Compare and contrast chromosomal DNA and plasmid

A

Chromosomal DNA carry genes needed for heriditary characteristics essential for bacterial growth and reproduction
Plasmid are small pieces of circular DNA that has nonessential info on it

96
Q

Compare the Kirby-Bauer test with the MIC test

A

Kb- tells us which antibiotic will work

Mic- tells us the dosage needed

97
Q

State the. Principle of the beta-lactamase test

Interpret results

A

Does the bacteria produce beta lactamase
Red-negative, no beta lactamase produced, sensitive to antibiotics
Yellow- positive, beta lactamase produced, resistant to antibiotics

98
Q

State media used for the antibiotic sensitivity test

A

Mueller-Hinton agar

99
Q

Define antibiotic

A

Chemicals produced by microorganisms that can inhibit growth of other micro organisms

100
Q

Define MIC

A

Minimal inhibitory concentration test

Lowest concentration of an antibiotic to inhibit growth of test organism

101
Q

Define e-test

A

Plastic coated strip that is a combination of mic and Kirby Bauer tests

102
Q

What are the he disadvantages to. Using abroad-spectrum antibiotic?

A

Contributes to escalating resistant bacteria

Wiles out normal flora so super infections can take place

103
Q

List eight factors that must. R controlled in reorder to standardize the Kirby Bauer test

A
  1. Rate if diffusion of antibiotic
  2. Stability of antibiotic
  3. Ph of culture medium
  4. Depth of culture medium
  5. Inoculum density
  6. Incubation time
  7. Incubation temp
  8. Concentration of antibiotic
104
Q

What does t he antibiotic test result sensitive indicate about the test organism?

A

The antibiotic works. On the pathogen