Brainscape's Knowledge GenomeTM

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


See full index

Micro > lecture 3- controlling microorganisms > Flashcards

lecture 3- controlling microorganisms Flashcards

1
Q

disinfection

A

destroys most microbial life, reducing contamination on inanimate surfaces

  • destroy vegetative (growing) cells
  • doesn’t kill bacterial spores
  • conditions too harsh to use on people
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

antisepsis

A

destroys most microbial life, reducing contamination on a living surface
-Use “antiseptics”, chemical agents that kill microbes

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

sterilization

A

destruction of all microbial life

-used for inanimate objects, never living tissue as too harsh

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

what are cells?

A

packages of water, genetics, proteins, sometimes have cell wall

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

highest resistance

A
  • bacterial endospores
  • pirons (infectious proteins)
  • no moving parts, low enzymes therefore few targets to kill
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

moderate resistance

A
  • Protozoan cysts (kind of like a spore)
  • fungal sexual spores,
  • naked viruses (does not have a membrane)
  • resistant bacteria (like some Gram+)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

least resistance

A
  • growing bacterial cells (expire quickly without water)
  • growing eukaryotic cells
  • enveloped viruses (c/membrane - HIV)
  • yeast
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how are viruses resistant?

A
  • dont need food

- many don’t need water

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

how are bacterial spores resistant?

A
  • some Gram-positive make spores
  • don’t need food
  • strong protein coat protects genetic material and enzymes inside
  • low water content
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how are some bacteria resistant?

A

ESP. Gram +

  • thick cell wall
  • resist desiccation (drying)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how are eukaryotes resistant?

A
  • protozoan cysts
  • fungal spores
  • Strong protein coats
  • Don’t need water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how is microbial death characterized?

A
  • cell structures dysfunctional (irreversible damage)
  • cant reproduce
  • Need microbicidal agent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

-cidal

A

killed

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

-static

A

not killed, won’t grow in mass numbers, removes them

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

what affects microbial killing rate

A
  • number of organisms (harder to kill lots - fewer cells, less sterilization time)
  • type of microbial population
  • concentration of decontaminating agents (less concentrated, less killing)
  • mode of action for agent
  • presence of solvents, organic matter, and inhibitors
  • environment temp and pH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how do you kill microbes?

A

target weaknesses
-denaturation of:
cell wall
cell membrane
enzymes
genetic material

17
Q

MOA: targeting cell membrane

A

-when cell membrane is disrupted, selective permeability is lost - cytoplasm leaks out causing cell death

18
Q

MOA: inhibiting enzyme functioning

A
  • proteins have a specific shape (native shape) when this is disrupted the protein becomes denatured
  • enzyme active sites can’t accept substrate to function
19
Q

explain the difference between moist heat and dry heat and how they kill microbes

A

moist heat is for coagulation and denaturation
dry heat removes water from organisms (incineration)

*moist heat is more destructive b/c water has ability to kill proteins within organism (takes less time sterilize)

20
Q

how does the autoclave work?

A

high pressure concentration of steam creating a destructive moist heat

21
Q

what is pasteurization used for? how is it accomplished?

A
  • disinfect beverages
  • heat is applied to liquid to kill pathogens, but doesn’t denature proteins (flavour and texture in tact)
  • doesnt kill endospores, and it is NOT STERILE
22
Q

what are the two methods of pasteurization?

A

flash: expose to 71.6°C for 15 seconds
Batch: expose to 63°C to 66°C for 30 minutes

23
Q

MOA: Ionizing radiation

A

ionizing: energy from-rays, gamma-rays and high energy UV light to liberate e- from atoms
* can penetrate and get hidden microbes, can inhibit proteins

24
Q

what is ionizing radiation used to sterilize?

A

food products, medical products

25
Q

advantages of ionizing radiation

A

speed, penetrating power, no heat

26
Q

Non-ionizing radiation

A

-causes mutations in DNA leading to cell death or function changes–> caused by low energy UV (thats why you wear sunscreen)

27
Q

uses of non-ionizing radiation

A
  • disinfection rather than sterilization
  • Hospital rooms, operating rooms, schools, food prep areas, dental offices
  • Treat drinking water or purify liquids
28
Q

MOA: Phenols

A
  • one initial disinfectants used
  • very penetrating
  • kill cells and spores and most viruses
  • denature proteins, membranes, cell walls
29
Q

MOA: Reactive ions

A 
includes chlorine, iodine, fluorine
-very penetrating
-kill cells, spores and most viruses
-strong oxidizers: they are hungry for electrons
(denature proteins and DNA)
30
Q

MOA: Alcohol

A

70% ethanol kills cells
better than 100% alcohol
b/c breaks membranes and denatures proteins.
**30% water contributes to coagulation
-Does not destroy bacterial spores
-More effective against enveloped than naked viruses

31
Q

MOA: detergents and soaps

A

detergents disrupt membranes (penetrates into membrane allowing cytoplasm to leak out)
-polar and non polar portions to help penetrate into cell membranes

32
Q

how is filtration used to decontaminate liquids

A
  • remove cells, but not most viruses

- non-denaturing and helpful for making serum, vaccines, antibiotics, purify water

Micro (12 decks)

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