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MicroBio > Lec. 2 Bacteria > Flashcards

Lec. 2 Bacteria Flashcards

1
Q

BASIC CHARACTERISTICS OF BACTERIA

A

•Prokaryotic cell structure
•Unicellular microorganisms
•Size range of most ≈ 0.5μ - 2.0μ
•Different species have different shapes, motility patterns
•Most bacteria have cell walls
•Some form endospores and capsules to protect from adverse environment
•Heterotrophic and autotrophic metabolism
•Reproduce asexually and parasexually
•Ubiquitous in environment, including colonization of higher organisms
-bacteria do not have a nucleus

-KNOW BACTERIAL STRUCTURE SLIDE 3

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2
Q

Unusual Giant Environmental Bacteria

A
  • 600μ
  • at 600 it can be seen with the naked eye
  • in some Australian fish
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3
Q

Shape of Single Bacterial Cells

A
  • coccus
  • bacillus
  • coccobacillus (In between the coccus & bacillus)
  • spirillum (WAVY)
  • spirochete (IT IS LIKE A CORK SCREW)
  • vibrio
  • Some bacteria are pleomorphic = have more than one form, usually cocci and bacilli
  • these are important b/c they are used in diagnosis
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4
Q

Aggregations of bacteria

A
  • diplococcus (two cocci come together as a pair)
  • streptococci (long chains of cocci)
  • tetrad (little packets of four in the same plane)
  • sarcinae (pack of 8)
  • staphylococci (cluster of grape)
  • bacillus (can link up and look like sausages [you need in your life])
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5
Q

Which shaped bacteria aggregate and which typically don’t?

A

-cocci and bacilli may aggregate but vibrio, spirillum, and spirochete shaped bacteria do not usually aggregate; they exist as single cells

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6
Q

Flagella

A
  • facilitate bacterial movement
  • tail like things at the end
  • can help them move to nutrients or away from harmful thing
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7
Q

axial filament

A

Axial filament is wound around the length of the bacterial cell between outer membrane an cell wall and attached at each end.

  • kind of movement that comes out is a cork screw like movement
  • similar structure to the flagella
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8
Q

Macroscopic aggregation bacteria

A
  • usually called “colonies”

- diff species have characteristic forms & color when cultured on agar

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9
Q

Colony shape

A

-round
-irregular
-filamentous
-rhizoid
-curled
SLIDE 16

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10
Q

Colony edge/margin

A

-entire
-filamentous
-undulate (irregular)
-lobate (irregular)
SLIDE 16

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11
Q

colony elevation (looking it through the perti dish

A

-raised
-flat
-convex
-umbonate
-growth into medium
SLIDE 16

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12
Q

colony colors

A 
•Depends on the species of bacteria
   –Whether the species 
     produces a pigment
   –How it reacts on culture 
     media with different 
     biochemical compositions
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13
Q

Nutrition (metabolism) of prokaryotic cells

A

•Nutrients are absorbed directly through cell wall and plasma membrane
•Many species secrete enzymes to break down materials in the environment before absorbing them
•Many species secrete antibiotics to inhibit growth of different species (this is a territorial thing)
•Some species have flagella to aid movement toward nutrient sources
•Metabolism is the the entire set of chemical reactions necessary to maintain life
-discovery of these that revolutionized medical treatment

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14
Q

Energy source

A

check slide 23

  • every living thing must have carbon and energy source
  • carbon : CO2 or Organic molecules
  • energy : Light or Chemical Reactions

MOST OF OUR ATTENTION WILL BE ON CHEMOHETEROTROPHS

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15
Q

Toxic Muck

A
  • California’s Algae Problem is worse than ever
  • happens mainly year farm water rushes there (has fertilizers and such)
  • blue-green algae-related toxin warnings remain at Russian River
  • Blue-green algae (cyanobacteria) are photoautotrophs that may produce toxins
  • dog dies on Russian river, positive for toxic algae
  • cyanobacteria is a very big public health concern
  • it is an infection
  • the way public health is dealing with it is by putting warning signs up
  • especially worse in Aug.
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16
Q

Effects of cyanobacteria toxins

A
  • Skin rash
  • Gastrointestinal problems
  • Respiratory failure, death
17
Q

Aerobe **

A

can grow ONLY in the presence of oxygen

18
Q

Microaerophilic **

A

can grow only in REDUCED oxygen

19
Q

Anaerobe **

A

can grow only in the ABSENCE of oxygen

20
Q

Facultative **

A

can grow in BOTH presence or absence of oxygen

21
Q

CATEGORIES OF PROKARYOTES BASED ON METABOLIC OXYGEN NEEDS

A 
•Why oxygen needs are important to know
    –Determines where we 
      encounter the 
      microorganism in nature
    –Determines where in 
      humans the 
      microorganism grows and 
      what disease it may cause
    –Determines how the 
      microorganism is 
      diagnosed in the  
      laboratory
    –May determine how the 
      infectious disease is 
      treated
22
Q

How bacteria protect themselves from the enviroment

A 
•*Use flagella to move away from a dangerous chemical or physical threat*
•MAIN PROTECTION: Most bacteria have cell walls 
    –Protects against changes in 
      osmotic pressure
    –usually composed of 
       peptidoglycan
•Formation of an endospore
    –usually composed of 
      double cell membrane, 
      extra peptidoglycan, 
      calcium, and other 
      chemicals to form 
      protective wall around the 
      nucleic acids in the spore
    –Protects against adverse 
      environment (heat, 
      dessication, chemicals)
•Formation of a capsule
   –usually composed of 
     complex polysaccharides
   –Protects against 
     phagocytosis (engulfment 
     and digestion) by immune 
     system cells of 
     human/animal host
23
Q

GRAM Something

A

•Crystal violet (CV) is taken into cell wall/plasma membrane of all bacteria.
•CV is fixed into cell wall/plasma membrane of all bacteria.
•Decolorizer penetrates outer membrane and cell wall of Gram negative bacteria and CV comes out; CV is not removed from Gram positives because peptido glycan wall is thicker
•Safranin stains all bacteria. Since CV is much darker than safranin, it masks the pink color of safranin and Gram positive organisms appear purple, but Gram negative appear pink.
-this is important b/c it classifies bacteria into different groups
SLIDE 34

24
Q

Acid-fast vs. non-acid fast

A

check slide 36

25
Q

Reproduction in Bacteria

A
  • Asexual reproduction is by binary fission; resulting individuals are genetically identical to original individual
  • “Parasexual” reproduction results in an individual that is genetically different from the cell that started the process; however, haploid sperm and ova are not produced so it is not a true sexual process
26
Q

Tranformation in bacteria

PARASEXUAL

A

check slide 41

- a way of getting genetic variation

27
Q

Transduction

PARASEXUAL

A
  • viruses that approach bacteria that are able to make a hole in the cell wall and incorporate its DNA into it
  • therefore goes from one bacterial cell to another… leading to variation
28
Q

Conjugation

PARASEXUAL

A

-Conjugation pilus… plasmid forms a little bridge between two cells and the plasmid is shared into a new cell that didn’t have plasmid before
SLIDE 44

29
Q

Eukaryota

A

fungi, plantae, protista, animai

30
Q

Prokaryota

A

bacteria & archaea

31
Q

Plasmid

A

contains genetic material (that is separate from the chromosome)

32
Q

Attachment pili (firmbriae)

A
  • sticks out straight from the bacteria, but it is there to prohibit movement
  • very important in some human disease, i.e. urinary track infection
33
Q

archea

A
  • bottom of volcanos
  • places where there is no other life form known
  • no archea has been known to give rise to human disease
34
Q

Gram-negative vs. positive

A
  • (-) has a thinner peptidoglycan than does gram (+) which has an extremely thick peptidoglycan
35
Q

carbonflushsin

A

-dies acid fast pink

36
Q

methylene blue

A

dies non-acid fast blue

37
Q

Sperm from a hermaphroditic worm can fertilize the ova of a different individual worm or its own. If a tapework fertilitizes its own ova with its own sperm and offspring results, what type of reproduction would this be considered?

A

A. asexual
B. sexual
C. parasexual
D. none of the above

ANS: parasexual

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