Bacteria Flashcards Preview

ODL > Bacteria > Flashcards

Flashcards in Bacteria Deck (34):
0

Size

0,5-2 micrometers

1

Gram staining

Staining with Crystal Violet
Fixing with Grams iodine
Washing with alcohol/acetone
Positive- purple
Negative - pink (counterstained with Basic Fuchsin)

2

Positive vs negative

Positive - peptidoglycan like cables, thicker walls, more robust
Negative - glycan makes single layer, additional polysaccharide membrane, resistant to toxic chemicals

3

Cell wall

Peptidoglycan
2D mesh-like polysaccharide chains
Cross linked by short peptides

4

Characteristics

Poles
Nucleoid
Unique ribosomes and polysaccharides
Membranes and central metabolic pathways similar to eukaryotes
Rapid reproduction

5

Reproduction

Cylinder elongation
Nucleoid replication
MreB
ParA separates chromosomes
FtsZ

6

MreB

Arranges material for new cell wall in a helix
Gene B of murein region
Murein = peptidoglycan
Related to actin

7

FtsZ

Filamentation, temperature sensitive
Forms z-ring
Related to tubulin

8

Shapes -8

Rods
Cocci (spheres)
Filaments
Vibrios (curved rods)
Spirilla (helical filaments)
Spirochaetes (wrapped around own flagella)
Actin bacteria (branched)
Mycelium (fungus-like)

9

Outside structures

Flagella
Fimbriae
Pili
Capsule

10

Flagella

Rotates like propeller
Polar or peritrichious

11

Fimbriae

Attaching to surfaces

12

Pili

Sex or type 4
Retractable

13

Capsule

Protection against desiccation
Attachment
Made from polysaccharides

14

Przetrwalniki

Endospores
After asymmetrical division
Mother cell+ forespore
Anthrax, tetanus

15

Types of reaction to oxygen

Aerobic
Facultatively anaerobic
Aerotolerant
Strictly anaerobic

16

Natural life cycle

Swimming form(chemotaxis)
Surface associated motility (swarming or twitching)
Microcolony
Biofilm
Quorum sensing

17

Cultivation

Agar (colonies)
Broth (rotary shaker, homogeneous dispersion)
Anaerobic jar (air replaced by CO2, N2, H2)

18

Classification by nutrition

Chemoheterotrophs
Chemoautotrophs
Photoheterotrophs
Photoautotrophs

19

Autotrophs

Source of carbon = CO2
Reducing power = H2, H2S, NH3, NO2-, Fe2+

20

Autotrophs - carbon fixing cycles -4

Calvin-Benson cycle (plants, Cyanobacteria, purple bacteria)
Reverse TCA
Hydroxypropionate pathway
Acetyl-COA p.

21

Heterotrophs

Source of carbon = absorbing organic molecules
Can't phagocitate
Large polymers need to be broken down before absorption

22

Chemo(...)trophs

Oxidise organic chemicals to get energy

23

Photo(...)trophs

Use light energy
Bacteriochlorophyll

24

Outdated method of classification

Bergey's manual of systematic bacteriology

25

Classification by 16S sequencing -4

Proteobacteria
Firmicutes
Actinibacteria
Smaller g- groups (actinobacteria)

26

Proteobacteria

Most of g- bacteria
Purple photosynthetic bacteria
Subdivided into alpha, beta, gamma, epsilon

27

Firmicutes

G+
Low GC content in DNA

28

Actinobacteria

G+
High GC content in DNA

29

Phylogenetic stuff -3

Most of smaller groups is g-, so g- are the ancestors
Lowest branches of tree are hyperthermophilic
Chlorophyll-based photosynthesis widely distributed = core adaptation developed early on

30

Important bacteria

E. coli
S. aureus
C. Difficile

31

Escherichia coli -8

Used as a host for gene manipulation
Forms 1% of gut bacteria
G-
Rod
Facultatively anaerobic
Chemoheterotrophic
Motile by peritrichious flagella
Some strains cause urinary tract infections

32

Staphylococcus aureus -9

G+
Cocci
Facultatively anaerobic
Firmicutes
Found in nasal membranes
Causes infection of wounds
Food poisoning
Secondary pneumonia
MRSA - methicillin resistant S. Aureus

33

Clostridium difficile -6

G+
Rod
Strictly anaerobic
Firmicute
Endospore forming
Can dominate gut flora after antibiotic therapy causing antibiotic-associated colitis