Lab mid term

Question 0

heat fixed

Answer 0

kills bacteria, makes them adhere to the slide and makes cytoplasmic proteins more visible

Question 1

basic stains

Answer 1

auxochrome becomes positively charged and is attected to the negative charges on the surface of most bacterial cells

Question 2

how does a basic stain work

Answer 2

add bacteria, heat fix slide, add stain, rinse with water, dry

Question 3

what makes a gram stain different from a simple stain?

Answer 3

there is a decolorization stage

Question 4

what dye is used as a primary stain?

Answer 4

crystal violet

Question 5

what does a mordant do?

Answer 5

iodine, enhances the crystal violet staining by forming a crystal violet-iodine complex, increases crystal size

Question 6

What type of alcohol is used in a gram stain?

Answer 6

ethanol alcohol

Question 7

what is the end result for gram negative cells in a gram stain?

Answer 7

pink/red
alcohol rinses crystal violet and safranin colors cell pink
alcohol breaks down thick lipid membrane causing the decoloriztion

Question 8

what is end result for a gram positive cell in a gram stain?

Answer 8

turns purple, thicker peptidoglycan wall traps crystal violet and iodine holding the color during alcohol rinse

Question 9

what are the steps in making a gram stain?

Answer 9

add bacteria, air dry
heat fix slide
add crystal violet
rinse with water
add iodine
rinse with water
rinse with ethanol
rinse with water
add safranin
rinse with water

Question 10

what makes acid fast stain different from gram stain?

Answer 10

uses acid alcohol instead of ethanol alcohol

Question 11

what is the point of acid fast stains?

Answer 11

determine which cells are acid fast positive and negative

Question 12

what is end result of acid fast positive cells

Answer 12

reddish-purple, carbofuschin is absorbed by cell through steam heating and melting the wax in the cell wall. resist acid alcohol rinse

Question 13

what is the end result of acid fast negative cells

Answer 13

blue color because the acid alcohol removes the carbofuschin

Question 14

list the steps in acid fast stains

Answer 14

add bacteria, let air dry
heat fix
add carbofuschin
rinse with water
rinse with acid alcholo
rinse with water
add methylene blue
rinse with water
dry

Question 15

a capsule stain is also what other kind of a stain

Answer 15

negative stain, stains the background

Question 16

capsules are composed of

Answer 16

mucoid polysaccharides or polypeptides that repel most stains

Question 17

what do you not do in a capsule stain

Answer 17

you do not heat fix, this causes cells to shrink could leave an artificial halo around cell that is not capsule

Question 18

what are the steps in a capsule stain

Answer 18

drop of broth
drop of congo red
do smear like a blood smear
air dry
add drops of acid alcohol
rinse with water gently
add safranin
rinse with water
blot dry

Question 19

endospore

Answer 19

dormant form of a bacterium

contain tough outer coating of keratin

Question 20

spores can be located where

Answer 20

central, terminal, subterminal

Question 21

what is a special step in endospore staining?

Answer 21

creating steam by boiling water, this allows for endospore to open

Question 22

list the steps in endospore staining

Answer 22

boil water
heat fix smear
add papertowel to smear
add malachite green stain
place over steam
keep adding stain to moist papertowel for 10 min
remove from stain
rinse with water
remove towel
rinse with water
stain with safranin
rinse with water
blot dry

Question 23

purpose of endospore staining?

Answer 23

find spore producer

Question 24

purpose of wet mount

Answer 24

see movement, use low light

Question 25

how to created hanging drop

Answer 25

``` apply petroleum jelly to slide add water to cover glass add bacteria to water place slide onto cover slip flip slide over so coverslip is on top ```

Question 26

what does petroleum jelly do in a hanging drop?

Answer 26

creates airtight seal that slows drying of drop

Question 27

what ingredients are in a mannitol salts agar

Answer 27

mannitol, sodium chloride and phenol red which is a pH indicator

Question 28

what is the range of phenol red

Answer 28

yellow below 6.8 red 7.4 to 8.4 pink above 8.4

Question 29

What does mannitol provide for the substrate

Answer 29

fermentation and medium differentiation

Question 30

phenol red shows what took place

Answer 30

fermentation

Question 31

mannitol salt agar is used for

Answer 31

isolation and differentiation of staphylococcus aureus | if present ferments the mannitol, produces acids and lowers pH to yellow, with yellow halo

Question 32

what is a common isolation technique

Answer 32

steak plate | quadrants or zig zag

Question 33

ubiquitous

Answer 33

organisms can be found everywhere

Question 34

shape can be described as

Answer 34

round, irregular, punctiform(tiny, pinpoint)

Question 35

margin can be described as

Answer 35

entire (smooth), undulate (wavy), lobate (lobed), filamentous, rhizoid (branched like roots)

Question 36

elevations can be described as

Answer 36

flat, raised, convex, pulvinate (very convex), umbonate (raised in the center)

Question 37

pigment production can be described as

Answer 37

opaque, translucent, shiny, dull

Question 38

refraction

Answer 38

bending of light

Question 39

what is the order of creating an image through a microscope

Answer 39

condensor lens (concentrates the light), objective lens which causes the light to refract also creating the real image, image magnified again by ocular lens then produces virtual image

Question 40

resolution

Answer 40

clarity of image | lower resolving power then higher resolution

Question 41

resolving power

Answer 41

actual measurement of how far apart two points must be for the microscope to view them as being separate.