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Microbiology > Chapter 2-3-4: Prokaryotic Cell Structure & Function > Flashcards

Chapter 2-3-4: Prokaryotic Cell Structure & Function Flashcards

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1
Q

Microscope

A

set of 2 or more lenses

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2
Q

Parts Necessary to Have Functional Microscope

A
  • light source
  • objective lenses
  • coarse & fine adjustment knobs
  • ocular lenses
  • diaphragm
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3
Q

Microscopy Concepts

A
  1. Magnification
  2. Resolution
  3. Illumination
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4
Q
  1. Magnification (Job of the Lenses)
A

increase in the apparent size of the specimen
- increases size of image (not object)
calculated by multiplying magnification factor of lenses
= objective x ocular

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5
Q
  1. Resolution
A

the minimum distance that two objects can be separated from one another, and still be recognized as distinct objects rather than 1 larger “fuzzy” object
- minimum distance between 2 objects where they still are seen as 2 different objects

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6
Q
  1. Resolution (Increasing Resolution)
A
  • oil: higher refractive index than air (allows light to stay and be collected into objective lens)
  • decreasing illumination wavelength (smaller the wavelength, better the detail ex. slide 10)
  • focusing illumination light (condenser) helps focus light
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7
Q

Resolution VS Magnification

A

Magnification: refers to the enlargement of the image
Resolution: refers to the ability to distinguish two objects located very close as being separated entities
(higher #= better the resolution)

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8
Q
  1. Illumination: Brightfield
A

method of lighting the specimen from opposite the objective
- specimen appears dark against a light background
- common method of lighting
- specimen interferes with light coming through

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9
Q
  1. Illumination: Darkfield
A
  • illumination of the specimen without projecting light directly into the objective
  • used to examine specimens which cannot be distinguished from the background
    • unstained; living
  • accomplished by specialized microscopic lighting techniques
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10
Q

Preparation & Staining of Specimens (Purpose & Process)

A

Purpose:
- increased visibility
- accentuates specific morphological features (enhancing)
- preserves specimens

Process:
- fixation
- staining
- visualization

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11
Q

Fixation

A

preservation of internal & external structures
- organism is killed and firmly attached to microscope slide

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12
Q

Methods: Heat & Chemical Fixing

A

Heat Fixing:
- good for maintaining external structures
- preserves overall morphology (not internal structures)

Chemical Fixing:
- protects fine cellular substructure and morphology of larger, more delicate organisms
- well preserved internal structures

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13
Q

Staining: 1. Dyes & Simple Staining- Dyes

A

Dyes: makes structures more visible & increase contrast
- cell structures more visible
- increasing contrast
- common features
- chromophore groups (color)
- ability to bind cells
- types
- basic + charged (bind to - charged cells ex DNA)
- acidic - charged

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14
Q

Staining: 1. Dyes & Simple Staining- Simple Staining

A
  • single agent
  • frequent used basic dyes
    • e.g crystal violet; methylene blue
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15
Q

Staining: 2 Differential Stains

A

divides microorganisms into groups based on their staining properties
Examples
- gram stain (most widely used- allows differentiation between gram + & gram - bacteria)
- acid-fast stain
- staining of specific structures

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16
Q

Gram Staining

A
  • Christian Gram (1884)
  • most widely used
  • two groups
    • Gm+, Gm-
    • differences in cell wall structure
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17
Q

Mordant

A

compounds that like to stick

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18
Q

Example of Getting Info From Name: Staphylococcus

A

staphylo- grape (bacteria sticks together)
coccus- sphere (sphere shaped)

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19
Q

Acid-Fast Staining

A
  • stains bacteria that is hard to stain
  • stains Mycobacterium- cannot be stained by Gram staining (cell wall made of thick lipids)
    • e.g. M. tuberculosis; M. leprae
    • staining characteristics: high lipid content in cell walls
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20
Q

Negative Staining

A
  • visualize capsules
    • colorless against a stained background
    • capsules are sensitive (do not use heat fixation) instead air-fix specimen
  • structure you’re trying to visualize stays colorless
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21
Q

Spore Staining

A
  • double staining technique
  • bacterial endospore (resistant) vs. vegetative cell (cell growing actively)
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22
Q

Flagellar Staining

A

mordant to increase thickness of flagella

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23
Q

Phase-Contrast Light Microscopy

A
  • living cells (not fixed)
  • no stain
  • light reflects from specimen
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24
Q

Electron Microscopy

A
  • transmission (cut specimen in very thin slices) see details IN specimen
  • scanning (use electrons to scan surface of the specimen) see details ON specimen
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25
Q

Overview of Prokaryotic Cell Structure

A
  • a wide variety of sizes, shapes, and cellular aggregation patterns
  • simpler than eukaryotic cell structure
  • unique structures not observed in eukaryotes
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26
Q

Cocci (s., coccus)- spheres

A
  • diplococci (s., diplococcus)- pairs
  • streptococci- chains
  • staphylococci- grape-like clusters
  • tetrads- 4 cocci in a square
  • sarcinae- cubic configuration of 8 cocci
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27
Q

Bacilli (s.,bacillus)- rods

A
  • coccobacilli- very short rods
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28
Q

Overview of Prokaryotic Cell Structure: Vibrio

A

“comma” shaped

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29
Q

Overview of Prokaryotic Cell Structure: Spirilla

A

s.,spirillum- rigid helices

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30
Q

Overview of Prokaryotic Cell Structure: Spirochetes

A

flexible helices

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31
Q

Can you differentiate between spirilla and spirochetes?

A

No, you can’t differentiate them unless they’re moving

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32
Q

Overview of Prokaryotic Cell Structure: Filamentous

A

form hyphae

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33
Q

Overview of Prokaryotic Cell Structure: Mycelium

A

branched hyphae

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34
Q

Overview of Prokaryotic Cell Structure: Pleomorphic

A

bacteria without a single characteristic shape (form)

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35
Q

Plasma Membrane

A

selectively permeable barrier, mechanical boundary of cell, nutrient and waste transport, location of many metabolic processes (respiration, photosynthesis), detection of environmental cues for chemotaxis

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36
Q

Gas Vacuole

A

an inclusion that provides buoyancy for floating in aquatic environments

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37
Q

Ribosomes

A

protein synthesis

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38
Q

Inclusions

A

storage of carbon, phosphate, and other substances; site of chemical reactions (microcompartments); movement

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39
Q

Nucleoid

A

localization of genetic material (DNA)

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40
Q

Periplasmic Space

A

in typical Gram-negative bacteria, contains hydrolytic enzymes and binding proteins for nutrient processing and uptake; in typical Gram-positive bacteria, may be smaller or absent

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41
Q

Cell Wall

A

protection from osmotic stress, helps maintain cell shape

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42
Q

Capsules and Slime Layers

A

resistance to phagocytosis, adherence to surfaces

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43
Q

Fimbriae and Pilli

A

attachment to surfaces, bacterial conjugation and transformation, twitching

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44
Q

Flagella

A

swimming and swarming motility

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45
Q

Endospore

A

survival under harsh environmental conditions

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46
Q

Bacterial Cell Envelope

A

contains plasma membrane and surrounding layers

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47
Q

Bacterial Plasma Membrane

A

(one of the major places to “dock” things)
- separation of cell interior from environment
- selectively permeable
- transport systems (food in, waste out)
- crucial metabolic processes
- respiration, lipid synthesis, etc.
- photosynthesis
- membrane receptors
- TM proteins
- detection of/response to chemicals

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48
Q

Bacterial Plasma Membrane cont.

A
  • highly organized, asymmetric, flexible, & dynamic
    asymmetric (what is facing outside is not always same as facing inside)
    dynamic (have the ability to change, gives ability to perform differently)
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49
Q

Bacterial Plasma Membrane Contents

A
  • phospholipids
  • proteins (2 main components)
    • peripheral membrane proteins- loosely associated with cell membrane
    • integral membrane proteins- in cell membrane
  • “fluid mosaic model”
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50
Q

Phospholipids are Ampipathic

A

both a hydrophobic and hydrophilic end

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51
Q

Phosphatidylethanolamine

A

main phospholipid in bacterial cells

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52
Q

Uptake of Common Required Nutrients: Macroelements

A

macronutrients (most cell dry weight)
- C,O,H,N,S,P
- K+, Ca2+, Mg2+, & Fe2+/3+
- required in relatively large amounts

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53
Q

Uptake of Common Required Nutrients: Micronutrients

A

trace elements
- Mn, Zn, Co, Mo, Ni & Cu (small amounts)
- required in trace amounts
- enzyme cofactors
- often supplied in water or in media components

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54
Q

Growth Factors

A

essential cell components (or precursors); cell can’t synthesize
- organic compounds

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55
Q

Classes of Essential Cell Components

A
  • amino acids
  • purines & pyrimidines
  • vitamins
    • function as enzyme cofactors

*cells cannot synthesize & required for enzyme activity

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56
Q

Mechanisms for Uptake of Nutrients

A
  • passive diffusion (some)
  • facilitated diffusion
  • active transport
  • iron uptake
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57
Q

Passive Diffusion

A
  • higher concentration to lower concentration
    e.g. H2O, O2 and CO2
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58
Q

Facilitated Diffusion

A

similar to passive diffusion
- not E dependent
- high concentration -> low concentration
- size of gradients impacts uptake rate

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59
Q

Facilitated Diffusion Differs from Passive Diffusion

A
  • carrier molecules (permeases)
  • smaller concentration gradient required
  • transport of glycerol, sugars & amino acids
  • more prominent in eukaryotic cells than in prokaryotic cells
  • doesn’t happen very often in prokaryotic cells
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60
Q

Facilitated Diffusion

A
  • rate increases more rapidly and at a lower concentration
  • rate reaches plateau
    • carrier saturation effect
  • (permeases) if there are 5 molecules inside cell, you cannot take anything more than 5 in until ones inside are fully saturated
  • high concentration gradient, high rate of transport
    • more outside, faster the process
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61
Q

Active Transport

A
  • against concentration gradient
    • energy-dependent process
    • energy comes from ATP or proton motive force
    • concentrates molecules inside cell
    • accumulates molecules in case of “starvation”
  • requires carrier proteins (permeases)
    • carrier saturation effect
  • example:
    • ABC transporters
    • secondary active transport
    • group translocation
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62
Q

ATP Binding Cassette (ABC) Transporters

A
  • very well ubiquitously conserved
63
Q

ATP Binding Cassette (ABC) Transporters: Components

A
  • pore: 2 transmembrane domains
    • nucleotide binding domains (ATP) - hydrolyzes ATP
      -substrate (or solute) binding protein
    • captures substance that is to be transported into cell
    • periplasm
    • deliver molecule to transporter
64
Q

ATP Binding Cassette (ABC) Transporters: Molecules Transported

A
  • sugars
  • amino acids
  • certain antibiotics
65
Q

Secondary Active Transport

A

use ion gradients to cotransport substances
- protons; gradient generated by metabolic processes (electron transport chain)
- symport- two substances both move in the same direction
- antiport- two substances move in opposite directions

66
Q

Symporter

A

same direction

67
Q

Antiporter

A

different direction

68
Q

Cotransporters

A

can transport 2 things at once

69
Q

Group Translocation

A
  • molecules modified during transport
    • energy-dependent processes
      e.g. phospoenolpyruvate: sugar phosphotransferase system (PTS)
  • transport of many carbohydrates
    • e.g. mannitol, glucose
  • components (e.coli/salmonella)
    • PEP
    • Enzymes I, IIA, IIB, IIC
    • heat-stable protein (HPr)
  • very common, widely distributed in bacteria
    • many facultative anaerobes
    • not in most aerobes
70
Q

Iron Uptake

A

iron is very difficult to transport
- ferric iron (Fe3+) insoluble; uptake difficult

71
Q

Iron Uptake: Siderophores

A

aid uptake, (sidero)- iron
- e.g enterobactin (e.coli)
- secreted; complexes with Fe3+
- complex transported

e.coli releases siderophores that change Fe into something (complex) that can be transported

72
Q

Iron Uptake: Transport (Gm-)

A
  • complex bound by receptor (outer membrane)
  • periplasm: either…
    • Fe3+ releases, enters directly, or
    • complex transported via ABC
73
Q

Bacterial Cell Wall

A
  • rigid structure; surrounds plasma membrane
  • consists of peptidoglycan (aka murein)
    • synthesis inhibited by penicillin
74
Q

Bacterial Cell Wall Functions

A
  • shape
  • protection (osmotic lysis)
  • may contribute to pathogenicity
  • may protect from toxic substances
75
Q

Periplasmic Space Contains Periplasm

A

periplasmic space exists between plasma membrane & cell wall (Gm+)
plasma membrane & outer membrane (Gm-)

76
Q

Periplasmic Enzymes

A

Gm-
Functions
- nutrient acquisition
- electron transport
- peptidoglycan synthesis
- modification of toxic compounds

77
Q

Exoenzymes

A

Gm+
similar functions as periplasmic enzymes

78
Q

Osmotic Lysis

A
  • hypotonic solutions
  • cell wall protects against osmotic lysis
    • protects plasma membrane that swells from the water
79
Q

Plasmolysis

A
  • hypertonic solutions
  • cell wall can’t protect against plasmolysis
    • as plasma membrane shrinks, cell wall cannot protect because it is exterior to membrane
80
Q

Two Major Bacterial Groups

A
  • Gm+ purple
  • Gm- pink
  • staining rxn probably due to cell wall structure
81
Q

Bacterial Cell Wall & Gram Staining

A
  • constriction of the thick peptidoglycan layer of Gm+ cells
    • prevents loss of crystal violet during decolorization step
    • therefore, purple
  • thin peptidoglycan layer of Gm- bacteria does not prevent loss of crystal violet
    • therefore, pink
82
Q

Peptidoglycan

A
  • polysaccharide formed from peptidoglycan subunits
  • backbone: alternating sugars
    • N-acetylglucosamine (NAG)
    • N-acetylmuramic (NAM)
  • provides agility & protection
83
Q

Gram Positive Cell Envelope: Cell Wall

A

primarily peptidoglycan
- may also contain teichoic acids

84
Q

Gram Positive Cell Envelope: Some Gm+ Bacteria

A

layer of proteins on surface of peptidoglycan

85
Q

Gram Positive Cell Envelope: Lipoteichoic Acid

A

help connect cell wall and layer of peptidoglycans

86
Q

Gram Positive Cell Envelope: Teichoic Acid

A

short molecules that help with connection between peptidoglycans
- specific to Gm+

87
Q

Gram Negative Cell Envelope: Cell Wall

A

thin peptidoglycan layer surrounded by outer membrane

88
Q

Gram Negative Cell Envelope: Outer Membrane

A
  • lipids, lipoproteins, and lipopolysaccharide (LPS)
  • no teichoic acids
89
Q

Gram Negative Cell Envelope: Braun’s Lipoproteins

A

connect outer membrane with peptidoglycan

90
Q

Gram Negative Cell Envelope: Adhesion Sites

A
  • not always present
  • direct contact between plasma membrane and outer membrane
  • may allow direct movement of material into cell
91
Q

Gram Negative Cell Envelope: Lipopolysaccharides (LPS)

A

3 parts
- lipid A
- core polysaccharide
- O side chain (O antigen)
e.g. Salmonella typhimurium LPS
the more external side chain has the ability to protect and generate an immune response

92
Q

LPS Functions: O Antigen

A
  • protects from host defenses
  • immunogenic
93
Q

LPS Functions: Core Polysaccharide

A

contributes to negative charge on cell surface

94
Q

LPS Functions: Lipid A

A
  • stabilize outer membrane structure
  • can act as an endotoxin
    outer membrane loses integrity, LPS molecule is elixed into the host, releases into host when bacterium dies
95
Q

Gram Negative Cell Envelope: Outer Membrane

A
  • protective barrier
  • more permeable than plasma membrane
    • presence of porins and transporters
      • porins: channels; small molecules (600-700 Da) anything smaller than
        primers, has specificity in size but not type (of what is let in)
96
Q

Layers Outside the Cell Wall: Capsules, Slime Layers, S-Layers

A
  • protection from host defenses (ex phagocytosis)
  • protection from harsh environmental conditions (ex desiccation)
  • attachment to surfaces
  • protection from viral infection or predation by bacteria
  • protection from chemicals in environment (ex detergents)
  • motility (gliding bacteria)
  • protection against osmotic stress
97
Q

Layers Outside the Cell Wall: Capsules

A
  • usually polysaccharides
  • well-organized; not easily removed
  • resist phagocytosis (ex Strep pneumoniae)
98
Q

Layers Outside the Cell Wall: Slime Layers

A
  • polysaccharides
  • diffuse, unorganized; easily removed
99
Q

Layers Outside the Cell Wall: S-Layers

A
  • not polysaccharides
  • structured layers of protein or glycoprotein
  • common among Archaea
100
Q

Layers Outside the Cell Wall: Glycocalyx

A
  • polysaccharide network
  • another term for capsule/slime layer
    (is not distinguished)- umbrella term
101
Q

Archaeal Cell Envelope

A
  • differ from bacterial envelope
    • both molecular & organizational
102
Q

Archaeal Plasma Membrane

A
  • composed of unique lipids
    • some have monolayer structure instead of bilayer structure

Why Monolayer?
archaea live in very harsh conditions. in high heat, a bilayer will break vs a monolater than can withstand harsh conditions

103
Q

Archaeal Cell Wall

A
  • Gm stain not useful, lack peptidoglycan
  • chemical makeup varies
104
Q

The Cytoplasmic Matrix

A
  • substance between membrane and nucleoid
    • ~70% H2O
  • packed with ribosomes and inclusion bodies
  • highly organized
    • cytoskeleton-like organization/function
105
Q

Bacterial Cytoskeleton

A

homologs of eukaryotic cytoskeleton components identified SEE TABLE ON SLIDE 67

106
Q

Bacterial Intracytoplasmic Membranes: Plasma Membrane In-Foldings

A

folds toward cytoplasmic matrix
found in…
- many photosynthetic bacteria
- bacteria with high respiratory activity
may be aggregates of…
- spherical vesicles
- flattened vesicles
- tubular membranes

107
Q

Bacterial Intracytoplasmic Membranes: Anammoxosome

A
  • membrane-bound organelle
  • found in anaerobic ammonia oxidation bacteria
  • unique to Planctomycetes
108
Q

Inclusions

A

aggregation of organic or inorganic material
types:
1. storage inclusions (specific to metabolism)
2. microcompartments
3. other inclusions

109
Q

Storage Inclusions: Carbon

A
  • glycogen inclusions
    • glucose
  • poly-beta-hydroxybutyrate (PHB) inclusions
    • beta-hydroxybutyrate
110
Q

Storage Inclusions: Phosphate

A

polyphosphate granules

111
Q

Storage Inclusions: Sulfur

A

sulfur globules

112
Q

Storage Inclusions: Nitrogen Storage

A

cyanophycin granules
- cyanobacteria
- large polypeptides (not from ribosomes)
- equal quantities of arg & asp

113
Q

Microcompartments

A
  • function other than metabolic stockpile
  • not bound by lipid bilayer
    ex) carboxysomes
  • cyanobacteria, CO2- fixing bacteria
  • concentration of CO2; enzyme localization
    • ribulose- 1,5- biphosphate carboxylase (RUBISCO)
114
Q

Other Inclusions: Gas Vacuoles

A
  • some aquatic prokaryotes (ex: cyanobacteria, Halobacterium)
  • buoyancy- vertical motility
  • aggregates of gas vesicles- how high or deep in you are
    • hollow cylindrical structures
115
Q

Other Inclusions: Magnetosomes

A
  • found in aquatic bacteria
  • contain iron
  • orient cells in magnetic fields (help bacteria find food)
116
Q

Ribosomes

A
  • complexes of protein and RNA
  • protein synthesis
    • associated with plasma membrane
    • matrix ribosomes
  • smaller than eukaryotic ribosomes
    • prokaryotic ribosomes: 70 S
      • large (50S): 5S + 23S + protein
      • small (30S): subunit 16S + protein
        S: unit that gives you an idea how far something will migrate through a concentration gradient
117
Q

Nucleoid

A
  • aka nuclear body, chromatin body, nuclear region
  • ~60% DNA, 30% RNA; 10% protein
  • location of chromosome
    • usually 1/cell
    • often circular; sometimes linear
  • nucleoid proteins probably aid in folding
    • differ from histones
  • usually not membrane-bound
    • irregularly shaped region
118
Q

Plasmids

A
  • usually small, closed circular DNA molecules
  • extrachromosomal
  • not required for growth and reproduction
    • genes for selective advantage
      ex) drug resistance
  • can be laterally transferred
    • transfer of plasmids from one molecule to another
    • drug resistance spread
  • widely used for molecular biological applications
119
Q

External Structures

A
  • pilli/fimbriae
    -bacterial flagella
  • archaeal flagella
120
Q

Fimbriae (Fimbria)

A
  • short, thin, hairlike, proteinaceous (made out of protein) appendages
    • up to 1,000/cell
  • attachment to surfaces
  • type IV fimbriae: twitching motility
  • have adhesions
121
Q

Adhesions

A

proteins that help with adhesion to surfaces and help to move around

122
Q

Sex Pili (Pilus)

A
  • similar to fimbriae
    • longer, thicker, less numerous (1-10/cell)
  • required for mating (e.g. conjugation)
  • specialized type of fimbriae
  • create a bridge
  • made of protein
123
Q

Bacterial Flagella

A
  • most motive bacteria (have flagella)
    • thin, rigid structures
    • up to 20 nano meters long
  • being synthesized from the top
124
Q

Patterns of Flagellar Arrangements

A
  • polar
  • monotrichous
  • amphitrichous
  • lophotrichous
  • peritrichous
125
Q

Flagellar Arrangements: Polar

A

at end of cell (pole of the cell)

126
Q

Flagellar Arrangements: Monotrichous

A

one flagellum

127
Q

Flagellar Arrangements: Amphitrichous

A

one at each end of the cell, @ each pole

128
Q

Flagellar Arrangements: Lophotrichous

A

cluster at one or both ends

129
Q

Flagellar Arrangements: Peritrichous

A

spread over entire surface

130
Q

Bacterial Flagella: Ultrastructure (3 Parts)

A
  1. filament
  2. hook
  3. basal body
131
Q

Bacterial Flagella: Ultrastructure- Filament

A

hollow, rigid cylinder; flagellin (protein that makes up filament)

132
Q

Bacterial Flagella: Ultrastructure- Hook

A

links filament to basal body

133
Q

Bacterial Flagella: Ultrastructure- Basal Body

A

series of rings that drive flagellar motor, docks flagella into bacterial cell

134
Q

Bacterial Flagella: Ultrastructure: Gram+ vs Gram - Cell

A

Gram +: 2 rings
Gram-: 4 rings

135
Q

Bacterial Flagella: Flagellar Synthesis (Self Assembly)

A
  • flagellin transported de novo through hollow filament
    • similar to Type III secretion
  • growth from tip
  • length/weight of flagellin isn’t identical through everything
136
Q

Bacterial Flagella: Flagellar Movement

A

flagellum rotates
- counterclockwise: forward motion (run), flagellum behind bacteria
- clockwise: disrupts run (tumble)
direction is not random

137
Q

Archaeal Flagella

A
  • not as well-characterized
  • differences
    • > flagellin subunit type
    • not hollow; thinner
    • hook/basal
    • rotation (Halobacterium)
      • CCW: pulls cell
      • CW: pushes cell
  • doesn’t rely on H+ motive force, but ATP hydrolysis
138
Q

Motility: Spirochete Motility

A
  • periplasmic axial fibrils: flexing/spinning movement
  • mechanism not well-understood
    flagella does not extend outside the cell
    expansion & contraction
139
Q

Twitching Motility

A
  • pili (type IV) involved
  • observed in group of cells (contracting)
140
Q

Gliding Motility

A
  • coasting along solid surfaces
  • no known visible motility surfaces
  • cyanobacteria, myxobacteria etc.
  • 2 models
    • polysaccharide secretion (expulsion of material from one end, propelling cell forward)
    • adhesion complexes (mucus secretions rotate)
141
Q

Chemotaxis

A

chemo- chemical
taxis- movement
- movement in response to a chemical
- movement towards/away from a chemical
- detected by cell surface chemoreceptors

142
Q

Absence of Chemoattractant

A

random movement
- runs & tumbles

143
Q

Chemoattractant Present

A
  • directional movement
  • caused by lowering the frequency of tumbles
144
Q

Bacterial Endospore

A
  • some Gm+ bacteria
  • dormant (not metabolically active) ; resistant to numerous environmental conditions
    • heat (boiling 1hr)
    • radiation
    • chemicals
    • desiccation
145
Q

Spore Structure: Exosporium

A

thin

146
Q

Spore Structure: Spore Coat

A

thick
- impermeable; chemical resistance

147
Q

Spore Structure: Cortex

A

peptidoglycan, helps with protection of core wall

148
Q

Spore Structure: Core Wall

A

surrounds protoplast
- nucleoid
- ribosomes
- inactive
- very little water helps maintain inactive state
- hydration can make endospore become active

149
Q

What Makes an Endospore so Resistant?

A
  • calcium (complexed with diplicolinic acid)
  • small, acid-soluble, DNA-binding proteins (SASPs)
  • dehydrated core
  • spore coat
  • DNA repair enzymes
150
Q

Sporulation

A

process of growing an endospore
- commences when growth ceases
- lack of nutrients
- complex multistage process
- can take hours to complete
- spores can last years to centuries
- process is reversible

151
Q

Transformation of Spore to a Vegetative Cell (Reverse of Sporulation)

A

complex, multistage process
1. activation
2. germination
3. outgrowth

152
Q

Activation

A
  • prepares spore for germination
  • often results from e.g heating
153
Q

Germination

A
  • spore swelling
  • rupture/absorption of spore coat
  • loss of resistance
  • increased metabolic activity
154
Q

Outgrowth

A

emergence of vegetative cell

Microbiology (2 decks)

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