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66 Cards in this Set

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Dye solutions/stains
used to color cells, or their background, thus making them more visible to the human eye.
Stains are composed of color-bearing ions in an aqueous solution. These carry either positive or negative charge.
Basic stains/dyes
have a positive charged (cationic) chromophores.
Acidic stains/dyes
have negatively charged (anionic) chromophores.
Bacteria have a slightly ________ charge on their surface. This causes cationic chromophores to be attracted to the bacterial cell. (Unlike charges do what?)
much easier to prepare

slides are less expensive and disposable

able to go to oil
What are the advantages of using the wet mount over the hanging drop techniques?
Anionic chromophores
________ __________ on the other hand will not stain the baterial cell itself but will stain the background instead. (Like charges do what?)
drys out

tends to dry out much faster than the hanging drop slide

limits the amount of time you can observe the motility and activity of an organism
What are the disadvantages of a wet mount technique?
self-directed movement
much more labor intensive both in preparation and cost

must be cleaned everytime rather than disposing of them.
What are the disadvantages of hanging drop technique?
don't dry out

able to see motility and activity of the organism
What are the advantages of using the hanging drop technique?
flagella, cilia, and pseudopods
How can microorganisms get around or move?
self-directed movement
The ability to have _____ ________ ________ confers a distinct advantage over nonmotile organisms.
positive chemotaxis

negative chemotaxis
A truly motile microbe can move toward a chemical stimulus, such as source of nutrient (________ _________) or away from a harmful substance (_________ __________).
allowing a motile organism to more easily penetrate our defenses, such as mucus membranes

more readily spread throughout the body.
What does motility imply for pathogens?
kinetic energy
What causes brownian motion?
Brownian motion or movement
non-directional, vibratory movement of small particles or cells, due to collisions with water molecules.
Proteus mirabilis

motile or nonmotile?
Staph. aureus

motile or nonmotile?
disinfectant dish
Where should you put the depression slides from the hanging drop technique after we are done with them?
dissecting needle
What should we use to remove the coverslip from the depression slide?
15 mins
How long should we leave the depression slides in the disinfectant dish?
What should you be wearing when you remove the depression slide from disinfectant dish, while cleaning, and placing it on the rack?
Differential staining technique
___________ ________ _________ involve more than one type of stain and differentiate (distinguish) btwn various types of bacteria and/or bring out specific structures.
Christian Gram
Who developed the gram stain?
cell wall
Bacteria satin differently with the Gram stain technique because of differences in their _____ _____ structure.
gram positive
What bacteria would have cell walls composed of thick layer of peptidoglycan and teichoic acid?
gram negative
What bacteria would have a much thinner layer of peptidoglycan, no teichoic acid and a high concentration of various lipids?
Some bacteria do not stain uniformly with the gram stain technique and are known as _____ ________.
What is the optimal time for the growth of an organism for the gram stain technique?
The ____ of the culture can also affect the results of a gram stain. Older cultures of gram positive bacteria tend to decolorize rapidly resulting in a false gram negative reaction.
gram variable
If the bacterial smear is too thick it may result in uneven staining and decolorizing and have the appearance of a ______ _________.
gram +
cell wall: peptidoglycan
gram -
Lipid A
crystal violet
What is the name for the primary stain in the gram stain technique?
1 min
How long do you leave the CV on for in gram stain?
gram's iodine
What is the mordant in the gram stain?
anything that anchors the 1' stain.
ethyl alcohol
What is the decolorizing agent in the gram stain technique?
As soon as color stops running from the smear, stop the ___________ process by rinsing the slide with tap water.
What is the counterstain for the gram stain?
1 min
How long do you leave the safranin on for in the gram stain?
bibulous paper
Blot the slide with _________ _____ and observe the slide under oil.
pink to red
A gram-positive cell will appear ______ and a gram-negative will appear _____ depending on how long you leave the safranin on for.
mycobacterium and nocardia
The acid fast stain technique (another differential stain) is primarily used in the identification of pathogenic bacteria in the genera ________________ and ________.
organ failure
The genus mycobacterium contains species that are significant human pathogens mycobacterium tuberculosis, the causative agent of ___________, Mycobacterium leprae, the causative agent of ________ and increasingly, in immunocompromised individuals, Mycobacterium avium-intracellulare, that can rapidly disseminate throughout the body causing _______ ________ and death.
Nocardia asteroids
__________ __________, a common inhabitant of soil and water, can cause opportunistic infections in the lungs and skin of humans.
mycolic acid
What these organisms have in common and what distinguishes them from other bacteria is their cell walls contain large amounts of a waxy lipid substance called ________ _____.
It is believed that __________, the primary stain in acid fast staining, forms a complex with the mycolic acid in the cell walls of acid fast bacteria making them more resistant to decolorization with acid alcohol after staining with carbolfushin.
vegatative cell
The metabolically active, reproducing form of a bacterial cell is termed the ___________ ______.

Certain genera of bacteria, by the process of ___________, are able to package their genetic information in an extremely resistant form, called a _______, and thus survive environmental conditions that would easily kill the vegatative cell.
The spore is formed within the vegatative cell and is termed an __________.
Upon the death and disintegration of the vegetative cell the endospore is released and becomes a free spore sometimes referred to as an _________.
Sporogenesis, in bacteria, is not a __________ process.
One vegetative cell will produce one spore and the vegetative cell has to rupture to release the spore. When environment condidtion improve, the spore will __________ to form one vegetative cell.
The formation of spores is a _________ mechanism.
Their thick ______ coat and low metabolic activity (they essentially dormant) renders spores extremely _________ to drying, heat, radiation, and toxic chemicals.
What are two medically significant genera of bacteria that are able to produce spores?

biological weapons
The ability of the spores of pathogenic species within these genera to survive normal __________ measures has profound implications for the food and healthcare industries as well as concerns of their use as __________ _______ of war or terrorism.
Many bacteria have a gelatinous coating exterior to their cell wall called a ___________.
chemical composition
The glycocalyx can vary in _________ and _________ composition among different species of bacteria.
slime layer
Some bacteria have a diffuse, amorphous glycocalyx layer termed _______ _______.
Others have much thicker glycocalyx that is tightly bound to the cell termed a _______.
Streptococcus pneumoniae
What pathogen produces capsules?
adding osmotic barrier
inhibits phagocytosis
storage of nutrients
List four ways in which a capsule can confer an advantage to the bacterium producing it.
destroy or shrink capsule
Why wasn't any heat used with this technique?