Brainscape's Knowledge GenomeTM

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


See full index

BIOL 230 > MicroLecE2Ch7 > Flashcards

MicroLecE2Ch7 Flashcards

1
Q

Sepsis

A

Microbial contamination

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

Asepsis

A

Absence of significant contamination

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

Sterilization

A

Removing all microbial life, including prions and spores

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

Commercial Sterilization

A

Killing C. Botulinum endospores

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

Disinfection

A

Removing pathogens

Usually referring to non-living things or inanimate objects

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

Antisepsis

A

Removing pathogens from living tissue

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

Degerming

A

Removing microbes from a limited area

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

Sanitization

A

Lowering microbial counts on eating utensils

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

Biocide/Germicide

A

Kills microbes

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

Bacteriostasis

A

Inhibiting, not killing, microbes

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

What is efficacy of treatment dependent on?

A

1) Number of microbes: larger the population of bacteria, longer time it takes and more difficult it is to kill
2) Environment: some types of environment can inhibit sterilization
3) Time of exposure
4) Microbial characteristics: does it have a capsule, is it a bacteria or a virus
5) Microbial death curve: effect of high or low initial load of microbes

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

What are the actions of Microbial agents?

A

1) Alteration of membrane permeability (disruption to membrane)
2) Damage to proteins (denaturing of proteins)
3) Damage to nucleic acids

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

Physical Methods of Control

A

1) Heat
2) Filtration
3) Low Temperature: inhibits microbial growth but does not kill it. So cold bacteria cannot reproduce
4) High Pressure: denatures proteins
Pro: sterilization
Con: thing must be able to w/stand high pressure
5) Desiccation: prevents metabolism; bacteriostatic
6) Osmotic Pressure: causes plasmolysis

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

Thermal Death Point (TDP)

A

Lowest temp at which all cells in a culture are killed in 10 minutes (variable is temp)

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

Thermal Death Time (TDT)

A

Time during which all cells in a culture are killed at a specific temp (variable is length of time)

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

Autoclave

A

Giant box w/a pressure jacket
Anything put in it for 15 minutes @ 121 C will be sterilized. Uses moist steam, which is at a higher temp.
Pros: full sterilization
Cons: whatever put it in must withstand the heat and steam

17
Q

Pasteurization

A

Reduces spoilage organisms and pathogens
Used on food which cannot be autoclaved
Applied at high heats but for very short time (flash heat)
Pros: can treat food and other things that cannot withstand autoclave without ruining them
Cons: cannot sterilize fully like an autoclave can

18
Q

Dry Heat

A

Kills by oxidation (such as in an oven)
Pros: one of few heat methods where there’s no moisture so it can be used on things that cannot get wet
Cons: takes a long time for sterilization 2 hours @ 170 C

19
Q

Filtration

A

Liquid is passed through a filter with tiny pores that do not allow microbes to pass through
Pros: can achieve sterilization if done correctly; does not use heat or pressure
Cons: only used w/liquids; doesn’t always achieve full sterilization

20
Q

Radiation

A

1) Ionizing: X-rays, gamma rays, electron beams
Pros: does not damage something, can penetrate further than UV/Non-ionizing, works for something that cannot w/stand heat and moisture
Cons: doesn’t sterilize, doesn’t travel through or deep into liquid, plastic, glass
2) Non-ionizing: UV
Pros: doesn’t cause damage to thing
Cons: doesn’t sterilize, doesn’t travel through or deep into liquid, plastic, glass

21
Q

What factors is effective disinfection dependent on?

A

1) concentration of disinfectant: high3er concentration doesn’t necessarily mean more disinfecting
2) Organic matter
3) Environmental pH
4) Time disinfectant was left on

22
Q

Use-Dilution Test

A

Determines efficacy of a disinfectant
Metal rings dipped in test bacteria are dried and then placed in disinfectant. Rings are transferred to culture media to see whether anything grows/bacteria survived treatment

23
Q

Disk-Diffusion Method

A

Disk soaked in a chemical disinfectant is put on a plage of bacteria, incubated, and then the zone of inhibition is measured

24
Q

Chemical Classes

A

1) Alcohols
2) Aldehydes
3) Biguanides
4) Chemical Food Preservatives
5) Gaseous Sterilants
6) Halogens
7) Heavy Metals
8) Peroxygens
9) Phenols
10) Quats
11) Surfactants
12) Supercritical Fluids

25
Q

Alcohols

A 
Denatures proteins, dissolves lipids
Requires water
Higher concentration not more effective
Pro: does not damage skin or tissue
Exs: ethanol, isopropanol
26
Q

Aldehydes

A

Inactivate proteins by cross-linking w/functional groups
Used in medical equipment
Ex: formaldehyde – used to preserve human tissue b/c it is a complete sterilant

27
Q

Biguanides

A

Disrupt plasma membrane

Ex: Chlorhexidine

28
Q

Chemical Food Preservatives

A

Organic acids inhibit metabolism – bacteriostatic
Control molds and bacteria in foods and cosmetics
Exs: sorbic acid, benzoic acid

29
Q

Gaseous Sterilants

A

Chemicals that have been pushed higher than their boiling points to the gas state
Denatures proteins
Pros full sterilization, does not damage
Cons: gas so you cannot see, has sweet smell, can kill you if yu breathe in

30
Q

Halogens

A

What they target to kill in the cell depends on the halogen
1) Iodine: alter protein synthesis and membranes. Tincture: in aqueous alcohol, Iodophor: in organic molecules
Pro: doesn’t harm tissue
2) Chlorine/Bleach: oxidizing agent, targets nucleic acids
Cons: corrosive

31
Q

Heavy Metals

A

Very high antimicrobial properties
What they target to kill depends on what the metal is
Denatures proteins
Threading silver through mop heads and clothing used in hospitals

32
Q

Peroxygens

A

Oxidizing agents
Used on contaminated surfaces
Exs: O3, H2O2, paracetic acid

33
Q

Phenols

A

Disrupt plasma membranes
Pro: very effective
Cons: very corrosive, doesn’t sterilize
Ex: Triclosan

34
Q

Quats

A

Positively charged polyatomic ions
Disrupts cell membrane
Used in food service sanitation

35
Q

Surfactants

A

Molecules that have polarity
NO antimicrobial properties, just removes organic matter like dirt and grime taking bacteria with it
Does not sterilize or sanitize
Exs: Soap, Acid-anionic detergents, Quarternary ammonium compounds

36
Q

Supercritical Fluids

A

Molecules that have unique characteristics, not quite in gaseous form but not quite in liquid form

37
Q

Microbial Characteristics

A

Most Resistant to Least Resistant:
Prions: amino acid sequence itself must be destroyed. Takes either extreme heat or very high levels of chemicals
Endospores of bacteria: resistant to desiccation, heat, chemicals
Gram-negative bacteria: has 2 membranes
Viruses w/out envelopes
Gram-positive bacteria: has 1 membrane
Viruses w/lipid envelopes

BIOL 230 (9 decks)

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