Brainscape's Knowledge GenomeTM

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


See full index

BIOL 2330 - microbiology > culture media + pure cultures > Flashcards

culture media + pure cultures Flashcards

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

what is culture media

A

preparations that are decided to support the growth of microbes

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

what are the physical forms of media

A

solid, semisolid, and liquid/broth

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

how do we solidify media

A

by using agar

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

how are solid and semisolid media distinguished

A

the percentage of agar used will determine which form we get

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

who introduced the solid culture media method for growing bacteria

A

robert koch

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

what are the forms of solidified agar

A

agar slant, agar deep, or agar plate

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

what tool is used to inoculate an agar slant

A

inoculating loop

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

what tool is used to inoculate an agar deep

A

inoculating needle

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

what are the types of media based on chemical composition

A

defined/synthetic media and complex media

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

what is defined/synthetic media

A

a medium in which all components and their concentrations are known

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

what is a complex media

A

contains some ingredients of unknown composition and/or concentration

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

what is complex media used for

A

used for most heterotrophic bacteria that one works with in an introductory lab

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

give some examples of complex media that one would use in an intro lab

A

nutrient broth, tryptic soy broth

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

what are some complex media components

A

tryptones, peptones, and extracts

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

what is tryptone

A

derived from a digest of casein by the enzyme trypsin

  • it’s an assortment of peptides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are peptones

A

protein hydrolysates prepared by the partial digestion of various proteins

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

describe the extracts used in complex medium

A

aqueous, usually from beef or yeast, and they contain a mixture of peptides, amino acids, minerals, vitamins

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

why is complex media useful

A

useful when you don’t know the nutritional needs of a particular bacterium you want to grow, or when you want a general purpose media that can fit the needs of many microbes

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

give examples of common complex media

A

tryptic soy broth, tryptic soy agar, luria broth, nutrient broth/agar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how do we solidify a liquid media

A

use agar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is agar

A

a polysaccharide that is exracted from a marine alga

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

where does agar come from

A

marine alga

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how much agar do we add to solidify a liquid media

A

1.5% agar is added (15g/L)

24
Q

list two advantages of agar

A

it isn’t degraded by most microbes

it liquifies at 100 C and can be cooled to 42-45 C before it hardens (easy to work with)

25
Q

list the functional types of media

A

general purpose, enriched, selective, differential, mannitol salt agar

26
Q

what is general purpose media

A

a media that supports the growth of many microbes (it’s like our baseline media)

27
Q

give examples of general purpose media

A

tryptic soy agar/broth

28
Q

what is enriched media

A

general purpose media supplemented by blood or other special nutrients

29
Q

give an example of enriched media

A

blood agar, chocolate agar

30
Q

what is selective media

A

favors the growth of some microbes and inhibits the growth of others

31
Q

give examples of selective media

A

eosin methylene blue agar (EMB), MacConkey agar, mannitol salt agar (MSA)

32
Q

describe what eosin methylene blue agar does (why is it a selective media)

A

used for E coli detection (suppresses growth of gram positive bacteria)

33
Q

describe what MacConkey agar does (why is it selective media)

A

it contains bile salts and crystal violet that inhibits the growth of gram positive organisms

34
Q

describe differential media

A

allows one to distinguish between dif groups of microbes based on their biological characteristics

35
Q

give an example of differential media

A

blood agar, EMB

36
Q

explain why blood agar is a differential medium

A

it can differentiate between hemolytic (can lyse RBCs) and nonhemolytic bacteria

  • hemolytic bacteria will have clear-ish rings around their colonies
37
Q

explain why EMB is a differential medium

A

allows one to distinguish between bacteria that can ferment/break down lactose from those that cannot

  • ie E coli, a lactose fermenter, turns metallic on EMB
38
Q

what type of medium is mannitol salt agar

A

differential and selective

39
Q

describe mannitol salt agar as a differential + selective medium

A

differentiates between those that ferment mannitol to produce acids from those that cannon

  • those that can ferment will form yellow zones around their colonies
  • is selective because salt concentration inhibits some bacterial growth
40
Q

define a pure culture

A

a population of cells arising from a single cell

41
Q

how can you derive a pure culture from a sample?

A

spread plate technique, streak plate technique, or the pour plate technique

42
Q

define colony

A

visible growth or cluster of microorganisms on an agar surface

43
Q

describe the spread plate technique

A

you spread a mixture of cells on an agar surface so that individual cells are well separated from each other. Makes use of a spreader

44
Q

describe the streak plate technique

A

involves spreading a mixture of cells on an agar surface so that individual cells are well separated. Makes use of an inoculating loop + the T streak method

45
Q

what is the T streak method

A

on a plate, go back and forth with your loop to distribute the concentrated cells. then streak from that area to a sterile part on the plate, and continue until it’s dilute enough that the colonies will be separated from each other

46
Q

describe the pour plate technique

A

sample is diluted several times, then put into empty petri dishes. Agar is poured in, and the plates are swirled to mix them, and then it hardens

47
Q

how do you make a pure culture broth

A

isolate one colony + put it into broth

48
Q

what do we look at during colony identification

A

morphology

49
Q

what morphological factors do we look for during colony identification

A

form, elevation, margin, texture, appearance, optical property, pigmentation

50
Q

list the different forms of colonies

A

punctiform (little dots), circular, filamentous, irregular, rhizoid (protruding/branched lines), and spindle

51
Q

list the different elevations colonies can have

A

flat, raised, convex (contact lens shaped), pulvinate (like a bubble), umbonate (irregular/lumpy)

52
Q

what are the different margins a colony can have?

A

entire, undulate, lobate, erose, filamentous, curled

53
Q

colonies more that 5mm in diameter or are irregular shape are likely made up of ___ cells

A

motile

54
Q

where on the plate is colony growth most rapid

A

at the edge of the plate

55
Q

why is colony growth most rapid at the edge of the plate

A

these cells have more access to oxygen and nutrients

56
Q

where is colony growth the slowest on a plate

A

in the center

BIOL 2330 - microbiology (30 decks)

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