Brainscape's Knowledge GenomeTM

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


See full index

MMI 133 > lesson four > Flashcards

lesson four Flashcards

1
Q

endotoxin

A
  • part of the cell structure-anchored in outer membrane
  • lipid molecule
  • released from the cell when the cell dies and disintegrates
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

exotoxin

A
  • produced by the bacterial cells, not a part of the cell strucuture
  • released from cell in many ways, damages other cells
  • protein
  • three functional types: enterotoxin, neurotoxin and cytotoxin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

bacterial metabolism

A

sum total of all chemical reactions within an organism
- catabolic: release energy
anabolic: store energy
- catabolism: chemical reactions that release energy, breakdown of organic compounds

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

anabolism

A

chemical reactions that require energy, building of complex organinc molecules from simpler compounds (stores ATP)

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

reaction rates

A

temperature dependent,
higher the temp, higher the reaction rate
- drawback: high temperature may kill cells (denaturation of proteins)

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

enzymes

A

Large protein molecules (biological catalysts)
* Make chemical reactions happen 100,000,000 X faster
* Substrate specific (what they work on)
* Have suffix “ase”
* May need cofactors – e.g. metal ions like zinc, magnesium
* Recyclable, unchanged during reaction

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

what cellular controls affect function of enzymes

A
  • temp
  • pH
  • saturation
  • salt concentration
  • inhibitors (mercury, silver)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

energy production

A
  • most microbes use carbohydrates as number 1 source for production of energy
  • glucose the most common nutrient source
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Two processes by which glucose is used

A

a. cellular respiration (aerobic, anaerobic)
b. fermentation
both processes need ATP to run

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

energy sources other than glucose

A
  • lipids: broken down by lipases
    protiens: broken down by proteases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

physchrophiles

A

-5 to +15 C

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

pyschrotrophs

A

20-30 C (listeria)

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

mesophiles

A

25-45 C

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

thermophiles

A

45-70 C

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

hyperthermophiles

A

70-110 C

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

Listeria monocytogenes

A
  • gram +, non-spore forming
  • facultatively anaerobic, motile
  • wide temp range: 3-42 C
  • wide pH range: 5.5-9.5
  • grow in high concentrations of salt (10%)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

listeria growth/survival

A
  • survives in low temp, high acidity and salt concentrations
17
Q

listeria habitat

A
  • soil, animal intestine through contaminated feed
18
Q

listeria symptoms in animals

A

CNS infections, goats, cattle (circling disease)

19
Q

listeria symptoms in man

A
  • food borne disease
  • CNS infections/death
  • abortion
20
Q

how listeria causes disease

A

ingestion of contaminated food
- invasion of bacteria through gastric epithelial cells
- gene ActA codes for this protein- an “invasin”
- grows in macrophages, destroys the phagolysosome with listerolysin
- intracellular and extracellular growth

21
Q

listeria clinical infection

A

meningitis, encephalitis, septicemia
-incubation period may be as long as 2 months
-elderly and immunocompromised at risk
mortality of CNS infections 20-50%
pregnant women can cause abortion or stillbirth

22
Q

listeria transmission

A
  • fecal-oral
  • foods implicated as a vehicle of infections: coleslaw, soft unpasteurized cheeses, turkey wieners, cold cuts, mushrooms and prepackaged salads, milk
23
Q

listeria epidemiology

A
  • hard to track because of long incubation period
  • responsible for 1700 cases of invasive disease
    fatal in about 1/3 of cases even with antibiotics
24
Q

listeria treatment

A

antibiotics for treatment but you have to diagnose the infection in time

25
Q

physical factors: pH

A

5-8 usual activity zone for human pathogens

26
Q

physical factors: osmotic pressure

A
  • isotonic solution is balenced
  • hypotonic: cell swells
  • hypertonic: cell shrinks, plasmolysis
27
Q

gaseous requirements for growth

A
  • strict aerobe: needs oxygen
  • facultative anaerobe: can be exposed to some oxygen
  • strict anaerobe: no oxygen
  • aerotolerant anaerobe: can have oxygen or not
  • microaerophile: small amounts of oxygen
28
Q

chemical factors

A
  • sources of C,N,O,S,P and trace elements
  • sources of organic growth factors (yeast extract in artificial media, cysteine or other amino acids)
29
Q

environmental factors: intracellular

A
  • evade WBC
  • need antibiotics that penetrate host cell membranes
  • some cannot be grown on artificial media
  • may be dependent on host cell for energy
30
Q

bacterial reproduction

A

binary fission

31
Q

bacterial generation time

A
  • dependent on media and growth conditions
  • aerobic bacteria usually grow faster than anaerobic (higher productions of ATP)
32
Q

bacterial growth kinetics

A

lag phase, log phase, stationary phase, death phase

33
Q

biofilms

A
  • bacteria like to live in communities
    dynamic: bacteria are not stuck, they can leave the biofilm and start a new focus of infection
  • slimy matrix with polysaccharides, proteins, DNA, bacteria
  • antibiotics ineffective against biofilms
34
Q

how to grow bacteria in the lab

A
  • nutrient material
  • agar: complex polysaccharide from algae for solid culture
  • bacteria grow in “colonies” – piles of bacteria where the original bacteria was placed on the surface of the agar filled plate
35
Q

hemolysis

A

breakdown of blood cells in agar plates
- used for presumptive bacterial identification of streptococcus species

36
Q

Alpha

A

partial breakdown of RBC (greening) around and under colony

37
Q

Beta

A

total breakdown (clearing) of RBC around and under colony

38
Q

gamma

A

no breakdown of RBC around or under colony

39
Q

complex media

A

used for growing human pathogens

40
Q

differential media

A

ingredients in media allow us to tentatively identify bacteria into major groups

MMI 133 (7 decks)

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