Brainscape's Knowledge GenomeTM

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


See full index

Microbiology > Lecture 2 > Flashcards

Lecture 2 Flashcards

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

What are the 5 techniques performed in the lab?

A

innoculation, incubation, isolation, inspection, identification

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

What is inoculation?

A

The placement of microorganisms into or onto culture media

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

What is a culture?

A

The growth of microorganisms with various media

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

What is a medium?

A

a nutrient used to grow microorganisms outside their natural habitat

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

What is an incubator?

A

chamber that is temperature-controlled (and sometimes control of other environmental factors), use for growth of microbes

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

What temperature is used for human pathogens?

A

temperatures fall between 20°C and 40°C for human pathogens

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

What happens during incubation?

A

During incubation, microbes grow and multiply, producing visible growth in the media; *growth indicates increase in NUMBER rather than increase in SIZE

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

What is a pure culture

A

just the one microorganism in the container

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

What is a mixed culture?

A

2 or more identified organisms in a container

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

What is minimal media?

A

media that only contains a few components

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

What is complex media?

A

contain at least one ingredient that is not chemically definable

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

What is selective media?

A

contains one or more components that inhibit the growth of a certain microbes but not others

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

What is differential media?

A

allows multiple types of microorganisms to grow but are designed to display differences among those microorganisms so that they can be distinguished from one another

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

What is reducing media?

A

contains a substance (i.e. thioglycollate) that absorbs oxygen or slows the penetration of oxygen

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

What is fermenation media?

A

contain sugars that can be fermented and a pH indicator that shows acid production as the
result of this reaction

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

what is transport media?

A

used to maintain and preserve specimens that have to be held for a period of time before clinical analysis

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

What is a colony?

A

a visible cluster of microbes on a solid medium

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

What is isolation?

A

Requires solid media with enough surface area to spread a culture for separation

Allows for identification of multiple organisms in mixed cultures

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

What is inspection and indentification?

A

Microbes can be identified through a combination of

microscopic appearance – wet mounts or staining

use of selective and differential media
characterization of cellular metabolism and products produced during growth, presence of certain enzymes

genetic and immunological characteristics

*A combination of these methods is used as usually one alone is not sufficient for positive identification

20
Q

What is resolution?

A

Ability to distinguish detail
Higher the resolution, clearer the picture
Resolving power – closest 2 points can be to each other and still be distinguished

21
Q

What is resolving power?

A

1) size of objective lens (larger the lens the greater the resolving power)
2) wavelength of light passing through specimen (shorter wavelengths tend to give better resolution)
3) refractive index of the material between the objective lens and specimen – oil, air…

22
Q

What is magnification?

A

Enlargement of an image

Requires a convex lens (thicker in center than at the edge)

23
Q

What is total magnification?

A

Number of times larger the image seen appears compared to the actual sample

24
Q

What is a wet mount?

A

Drop of liquid containing microorganisms on a slide with a coverslip on top
Allows you to see the true size and shape, motility

25
Q

What is a stain?

A

Increase contrast, bind to certain parts of microorganisms, allow them to be visible
Vital stains – stain living cells, can be added directly to a wet mount
Some staining requires fixation of the cells

26
Q

What is fixation?

A

Getting the organism to stay on the slide

27
Q

What are the types of dyes?

A

Basic dyes – positively charged (safranin, basic fuchsin, crystal violet, methylene blue)
Acidic dyes – negatively charged (Eosin, acid fuchsin, congo red)
Mordants – intensify staining, increase the cell’s affinity for a dye

28
Q

What are the types of stains?

A

Simple

Differential

Special

29
Q

What are simple stains?

A

Basic dyes that allow the cell to be visible, all cells are stained the same color

30
Q

What are differential stains?

A

Distinguish between types of organisms based on how they stain

31
Q

What are the 3 steps of differential staining?

A

Three steps:
primary staining – same as simple staining
destaining – removes stain in certain cells
counterstaining – stains parts of cells that were destained to allow them to be seen

32
Q

What is Gram’s Stain?

A

Divides bacteria into 2 groups, Gram positive and Gram negative

33
Q

What is acid fast stain?

A

Used to identify Mycobacterium tuberculosis, only stains mycobacteria and some actinomycetes (called acid fast bacteria)
These bacteria resist destaining because of a waxy material in their envelope
Acid fast bacteria stain red, non-acid fast stain blue

34
Q

What are structural stains?

A

cell wall, flagella,

capsule

35
Q

What is an example of a hard to stain bacteria?

A

spirochetes

36
Q

What is negative stain?

A

stains everything except structure you’re looking for (capsule stain)

37
Q

What are the types of microscopy?

A

Brightfield, Darkfield, Phase contrast, Differential,

Fluroscent, confocal, electron, transmission, and scanning

38
Q

What is Brightfield Microscopy?

A

Brightfield is a stain and the light waves move in sync.

You have to have stain in this type and you have to set the right settings

39
Q

What is darkfield microscopy?

A 
Live organisms (wet mount)
Makes the field dark and the organisms glow
40
Q

What is phase contrast microscopy?

A

Allows visualization of live, unstained organisms (wet mount)

Phase rings in objective lens and condenser that send some light rays through specimen, some around it (where as brightfield sends rays straight through the specimen), allowing for visualization)

41
Q

What is differential microscopy?

A

Like the phase-contrast microscope, the differential interference contrast (DIC) microscope provides a detailed view of unstained, live specimens by manipulating the light.
two prisms that add contrasting colors

42
Q

What is fluorescence microscopy?

A

Used in research and diagnostically. Stain only binds to a certain organism so when you had the stain to the sample and something glows then that is what you are looking for. You are using dyes that glow under certain lights. Different wavelengths cause different things to glow in different colors

43
Q

What is confocal microscopy?

A

Really nice clean images.

Z stacks take a bunch of pictures and stack them to make a 3d image

44
Q

What is electron microscopy?

A

Used for examining objects smaller than 2uM.

Uses a beam of electrons instead of light (much shorter wavelength, so get much higher resolution)

45
Q

What is transmission microscopy?

A

Fixed samples that are dead

46
Q

What is scanning microscopy?

A

Beam of electrons is directed over the surface of the specimen, knocking electrons out of the surface of the specimen. These secondary electrons are transmitted to an electron collector, amplified, and used to produce a 3-D image

Microbiology (12 decks)

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