Brainscape's Knowledge GenomeTM

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


See full index

Microbiology > Lab Practical 2 > Flashcards

Lab Practical 2 Flashcards

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

Generation time

A

Amount of time from the formation of a cell until the cell divides.

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

Phases of bacterial enumeration

A

Lag, Log, Stationary, Death

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

Why is there a lag phase

A

Bacteria are adjusting to their new environment.

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

At what phase is it best to collect bacteria in lab?

A

Log or early stationary phase

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

What is enumeration?

A

The process of counting or calculating the number of cells in a population or sample. We used aerobic plate count.

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

What do you call the number of viable cells in a sample?

A

Colony forming units (CFU)

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

What is serial dilution?

A

Technique used to reduce the number of CFU in a sample.

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

Technique used in bacterial enumeration to evenly distribute a liquid sample on the surface of agar.

A

Spread plating

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

CFU per mL =

A

of colonies on a plate x ( 1/ dilution factor of the plate)

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

of colonies on a plate that can be used in bacterial enumeration calculations

A

30-300

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

What are exoenzymes?

A

Exoenzymes are secreted by bacteria into their environment. They can function as toxins, or to provide nutrients to the cell.

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

What is gelatinase?

A

A type of protease that catalyzes the hydrolysis of gelatin into its component amino acids. Proteases are a group of enzymes that break down proteins. Pathogens can use this to break down connective tissue in the process of invasion. This is a virulence factor.

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

What is a protease?

A

Proteases are a group of enzymes that break down proteins

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

Nutrient gelatin

A

Differential. Used to determine if an organism produces gelatins. Contains gelatin (collagen), peptone, and beef extract. Collagen is a protein.

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

What indicates that an organism produces gelatinse?

A

The solid gelatin will become liquid at room temperature. Must be at temperatures lower than 28 C, as it is always liquid at 28.

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

What is amylase?

A

An exoenzyme used to break down large molecules into their monomers so they can be taken in to the cell.

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

What does amylase do?

A

Catalyzes the hydrolyses of amylose (starch) into maltose and glucose. Often used in the brewing industry, and converts corn starch to high fructose corn syrup.

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

Starch agar

A

Differential. Detects hydrolysis of starch by a bacteria.

Nutrient agar that contains soluble starch. After incubation plate is covered with iodine to detect the presence of a zone of no cleaning.

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

What will an organism that can hydrolyze starch show?

A

A distinct halo (the zone of clearing), showing that the starch around the culture was digested.

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

Starch agar results: bacterial growth with a zone of cleaning

A

Organism produces the enxoenzyme amylase

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

Starch agar results: bacterial growth, no zone of clearing

A

Organism does not produce the exoenzyme amylase

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

Sulfide Indole Motility medium (SIM) detects…

A

Used to detect:

  • sulfide production
  • indole production
  • motility
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

SIM medium characteristics

A

Differential. Contains sodium thiosulfate, ferrous ammonium sulfate, casein, and 3.5% agar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is sodium thiosulfate recused to?

A

Hydrogen sulfide (H2S). This reacts with the iron in ferrous ammonium sulfate, forming ferrous sulfide.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How does ferrous sulfide appear on SIM?

A

As a black precipitate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Black precipitate on SIM plate

A

Organism produces hydrogen sulfide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

No black precipitate on SIM plate

A

Organism cannot produce hydrogen sulfide.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the amino acid tryptophan broken down into?

A

Indole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is used to determine the presence of indole on a SIM plate?

A

Kovak’s reagent, which will turn red if indole is present.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Red Kovak’s reagent on SIM plate

A

Organism produces indole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Kovak’s reagent didn’t turn red on SIM plate

A

Organism does not produce indole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the purpose of the 3.5% agar in SIM?

A

It creates a medium that is solid enough to prevent the diffusion of non-motile bacteria.

33
Q

How is motility indicated in SIM?

A

Growth or cloudiness outside of the single inoculation stab.

*obligate aerobes do not grow well in stabs, can only be used for facultative anaerobes or anaerobes.

34
Q

What is catalase?

A

Enzyme found in bacteria and other organisms that catalyzes the conversion of peroxide anions into water and oxygen, protecting the organism from oxidative damage.

35
Q

Catalase test

A

Differential. Determines if an organism produces the enzyme catalase.

Hydrogen peroxide added to sample on microscope slide. If bubbles form, catalase is produced.

36
Q

No bubble formation on catalase test

A

Organism does not produce catalase

37
Q

What does cytochrome oxidase do?

A

Enzyme responsible for reducing oxygen in the last step of aerobic respiration, forming H2O as an end product.

38
Q

What does a blue result (after 20s) on a DrySlide indicate?

A

That an organism produces cytochrome oxidase

39
Q

What is fermentation?

A

Organism oxidizes NADH back into NAD+, produces ATP, without oxygen.

40
Q

Types of fermentation

A

Homolactic
Heterolactic
Mixed acid
2,3 butanediol

41
Q

Phenol Red Carbohydrate Broth

A

Differential. Determines if a bacteria can ferment certain sugar, and if acids or gases are produced as end products.

42
Q

Phenol Red broths (4)

A

Glucose
Lactose
Sucrose
Mannitol

43
Q

What is phenol red?

A

A neutral pH indicator

44
Q

Name of tube inside phenol red broth?

A

Durham tube

45
Q

Phenol red test: broth is yellow, bubble forms

A

Organism can ferment whatever sugar is in the broth, and produces acid

46
Q

Phenol red test: broth turns orange

A

Obligate aerobe converted the sugar into acid, but not using fermentation.

47
Q

Man who did experiments on mice that led to understanding of bacterial transformation

A

Frederick Griffith

48
Q

Scientists that continued Frederick Griffith’s work on bacterial transformation

A

Avery, McLeod, McCarty

49
Q

What is transformation?

A

The uptake of naked DNA from the environment by a bacterial cell

50
Q

What do you call the ability of a bacterial cell to be transformed (take in DNA from the environment)?

A

Competence

51
Q

What are the steps in making E coli have artificial competency?

A

Being in a solution of CaCl2 (calcium chloride), subjected to heat shock.

52
Q

What is the purpose of the heat shock step?

A

Forms transient pores in the cell walls, giving a path for the plasmid to enter through.

53
Q

What is the purpose of the Calcium chloride?

A

The Ca ions bind to the bacterial cell wall, neutralizing it

54
Q

pGLO plasmid

A

Contains ampicillin resistance and the production of the green fluorescent protein GFP

55
Q

What promoter controls the transcription of the GFP gene?

A

The promoter for arabinose metabolism. There must be arabinose in the growth medium, so the ara promoter becomes active, so that GFP will be synthesized.

56
Q

What gene causes the glowing?

A

GFP

57
Q

What does beta-lactamase enzyme do?

A

Confers resistance to ampicillin. Only bacteria that have been transformed will be resistant to ampicillin.

58
Q

What gene codes for beta-lactamase enzyme?

A

bla gene

59
Q

What will E. coli do on plates with ampicillin.

A

E. coli that has not been transformed will not be able to grow on plates containing ampicillin

60
Q

What is a promoter?

A

Region of DNA that initiates transcription of a piece of DNA

61
Q

Final e- receptor in fermentation?

A

An inorganic material

62
Q

Top of phenol red tube is red, bottom yellow?

A

Tube was left to incubate for too long.

63
Q

End products of homolactic fermentation

A

Lactic acid

64
Q

End products of heterolactic fermentation

A

lactic acid, ethanol, CO2

65
Q

End products of mixed acid fermentation

A

lactic accidentally, succinc acid, acetic acid, formic acid, ethanol, hydrogen, CO2

66
Q

End products of 2,3 butanediol fermentation

A

lactic acid, formic acid, ethanol, 2,3 butaneldiol, hydrogen, CO2

67
Q

Antimicrobial definition

A

General term for a compound that negatively affects the growth of microbes.

68
Q

Broad spectrum drugs target….

A

A common aspect of all bacterial cells.

69
Q

Narrow spectrum drugs usually attack…

A

an aspect of cell physiology not found in all bacterial cells

70
Q

Aminoglycosides

A

Streptomycin(S), kanamycin (K), neomycin (N). Prevent protein synthesis.

71
Q

Bacitracin (B)

A

Prevents cell wall synthesis

72
Q

Beta-Lactams

A

Penicillin (P), amoxicillin (AmC), prevents formation of peptidoglycan in the cell wall

73
Q

Chloramphenicol (C)

A

Disrupts protein synthesis

74
Q

Fluoroquinolones

A

Ciprofloxacin (CIP) prevents replication by binding to DNA gyrase

75
Q

Macrolides

A

Erythromycin (E), disrupts protein synthesis

76
Q

Tetracyclines

A

Tetracycline (TE), interfere with protein production

77
Q

Sulfanomides/Trimethoprim

A

Sulfamethoxazole with trimethroprin (SxT) inhibits folate synthesis

78
Q

Name of test with all the little dots on the tray

A

Kirby-Bauer Disk diffusion assay

79
Q

UV light causes….

A

…the formation of thymine dimers in DNA molecules, which block DNA replication and transcription, killing bacteria.

Microbiology (7 decks)

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