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42 Cards in this Set

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A BLANK microscope uses only a single lens.
simple
BLANK microscopes use light to view specimens.

What are the four types?
Light

Bright field, dark field, phase contrast, and fluorescent
BLANK microscopes use a beam of electrons and magnets to allow higher degrees of magnification
Electron (EM)
What type of microscope is used in the lab?
Bright field and compound microscopes
BLANK lens is the one you look through

BLANK lenses are the lens directly above your specimen
Ocular

Objective
What are the two lenses that focus the light rays coming from the light source onto the specimen?
The condenser
What is magnification?

What is total magnification?
The enlargement of a specimen

Magnification of the ocular lens X objective lens
What refers to the ability of the microscope to stay in focus when adjusting the objective lens to a higher power?
Parafocal
What refers to the ability of the microscope to keep the specimen you have in focus centered with increases in magnification?
Parcentric
What is the area you are viewing through the microscope?
field of view
What is the smallest distance two closely spaced objects can be separated and be differentiated as two individual objects?
Resolution
What is an increase in magnification without the required increase in resolution?
Empty resolution
What is it called when there is an increase in magnification and subsequently a decrease in the 3D power of the microscope?
Depth of field
What is the environment created to study microorganisms called?

What does this environment provide?

What are the four types?
Culture media

Nutritional requirements

Broth, agar deep, agar slant, and agar plate
What is a solidifying agent, derived from seaweed, which is a complex carb and has no nutritional value?
Agar
How is the multiplication of a single cell species represented?
Colonies on the media
What is an agar deep?

What is an agar slant?

What is an agar plate?
Agar deep is agar poured straight into a test tube

Agar slant is agar poured into a slanted test tube

Agar plate is agar poured into sterile petri dishes
When is chemically defined media used?
When an organism's exact nutritional needs and chemical makeup are known
What is complex media?

What are the two types of complex media used in the lab?
Commonly used in the lab and made from items such as peptones, beef, and yeast extract

Tryptic soy agar (TSA) and Tryptic soy broth (TSB)
What is a complex medium that has additional additives(s) added to it to allow the growth of fastidious organisms?

What are examples of the additives?
Enriched media

Vitamins, plant extract, animal extract, or blood
What is a method used to destroy all microorganisms and spores in a medium?

What is a specific method called? How does it work?
Sterilization

Autoclaving. It sterilizes media by using pressure, high temperature, and hot steam in a chamber.
Why is staining used in the lab?
To better view microorganisms under a microscope
Define the following morphologies of bacterial cells
1. Cocci
2. Bacilli
3. Vibrios
4. Coccobacilli
5. Spirilla and Spirochetes
6. Pleomorphic
1. Spheres
2. Rod-shaped
3. Slightly curved rods
4. Short rods
5. Spiral shaped
6. Multiple shapes
Define the following arrangements of bacterial cells
1. Diplo
2. Staphylo
3. Strepto
4. Tetrad
5. Sarcina
1. cells arranged as pairs
2. cells arranged in grape-like clusters
3. cells arranged in chains
4. a quartet of cells
5. two quartets of cells that form a 3D "cube"
What are the two steps to be completed before staining a specimen?
Smearing the specimen on a plate

Fixing the specimen to the plate using heat
A BLANK stain stains the specimen, but not the background.

Where does the light pass through?
Direct stain

The background
A BLANK stain stains the background, but not the specimen.

Where does the light pass through?
Negative stain

The cells
A BLANK stain stains a bacterial smear with a single dye.

What is colored? What is it used for?
Simple stain.

The cells.

Used to determine morphology, size, and arrangement of bacterial cells.
A BLANK stain is a stain that uses at least three chemical reagents on a smear.

What are the three reagents used?
Differential

Primary stain, Decolorizer, and Counterstain
What does the primary stain do?

The decolorizer?

The counterstain?
Initially give color to the cells

Gives a color contrast

Gives a contrasting color from the primary stain to the cells that were decolorized
What is the Gram stain? Who was it developed by? What's its purpose?
It is a type of differential stain.

Developed by Hans Christian Gram.

Used to differentiate bacteria based on their cell wall composition.
Gram stains differentiate most bacterial species into what? (2)

What are the four reagents used in a Gram stain?
Gram positive and gram negative bacteria

1. Crystal violet (primary stain)
2. Gram's iodine (mordant)
3. Ethanol (decolorizer)
4. Safranin (counterstain)
BLANK bacteria have cells walls with thick layers of peptidoglycan.

What color do they stain as?
Gram positive bacteria

Purple
BLANK bacteria have cells walls with a thin peptidoglycan layer.

What color do they stain as?
Gram negative bacteria

Pink/red
Briefly describe the four steps of a Gram Stain reaction
1. Primary stain uses crystal violet to stain all cells purple.

2. A mordant, iodine, is used to reinforce attachment of the purple dye to the negatively charged cell wall, membrane, and cytoplasm of the bacteria.

3. 95% ethanol is used as a decolorizer to dehydrate cell walls, trapping the purple in GPB, or washing it away in GNB.

4. Safranin is used as a counterstain to stain the decolorized cells as pink/red
A BLANK BLANK contains only one type of microorganism.

Important in ID and classification of bacteria
Pure culture
What is it called when microorganisms are transferred from one medium to another?
Subculturing
What is a type of subculturing that uses sterile instruments under sterile conditions?
Aseptic transfer
What are three bacterial isolation methods employed in the lab?
Streak plate technique, spread plate technique, and pour-plate technique
What is it called when a single colony is aseptically transferred to another medium?
Pure stock culture
BLANK BLANK is the macroscopic observation of a colony's growth plate

What 7 other criteria are used to describe a colony's morphology? (FEMOPS Su)
Colony morphology

Form
Elevation
Margin
Optical property
Pigment
Size
Surface
What is the difference between colony morphology and cell morphology?
The former refers to form and structure of COLONIES ON THE PLATE. (macroscopic)

The latter refers to form and structure of CELLS WHEN STAINED. (microscopic)