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MICROBIOLOGY
Cell Biology of Bacteria
Northland Community & Technical College
Instructor
Terry Wiseth
2
BACTERIAL FACTS
Scientists have named and described more than 4,000 species of bacteria
New ones are discovered so rapidly, however, they estimate the number of unknown species in the millions
Almost every time scientists search among bacteria in a soil or water sample, they discover previously unknown species
3
The overwhelming majority of bacteria are harmless to humans or animals
Bacteria get virus infectionsAntibiotics and other bacteria-derived
materials are the basis of a $50 billion annual market for biotechnology products
Oil spills are cleaned primarily by bacteria that feed on oil
BACTERIAL FACTS
4
About 10 percent of human body weight and 50 percent of the content of the human colon is made up of bacteria (Escherichia coli)
each square centimeter of human skin hosts an average of 100,000 bacteria
Washing removes many, but they reproduce so quickly--doubling every 20 minutes--that the population is restored in hours
BACTERIAL FACTS
5
So many bacteria live underground that their total weight has been estimated at 100 trillion tons
If these microbes were spread over Earth's land surface, they would make a layer five feet thick
BACTERIAL FACTS
6
CLASSIFICATION
Microbesorganisms smaller than the eye
can detectbacteriafungiprotistsvirus
7
CELL TYPES
ProkaryotesEukaryotes Viruses
8
PROKARYOTES
Monerabacteria1
micron diameter
9
EUKARYOTESalgae, protozoa
and fungi5 - 100 microns
10
VIRUSES
neither prokaryotes nor eukaryotes informational parasiteseach kingdom has its own
associated viruses
11
MICROBIAL SIZE
Virus 0.05 to 0.1 microns
Bacteria 0.5 to 1.5 microns
Red blood cell 5 microns
Sperm 60 microns
12
MICROBIOLOGY
disease
agriculture
food and drink
chemical products
basic research
biotechnology
PROKARYOTESVS
EUKARYOTES
14
CELL CHARACTERISTICSProkaryote Eukaryote
Chromosome Single circular
ChromosomePaired linear
Chromosome locationNucleoid(no membrane)
Chromosome locationNucleus(membrane present)
Nucleolus Absent Nucleolus Present
Extra chromosomalDNA in Plasmid
Extra chromosomalDNA in Mitochondriaand Chloroplast
Cellular Respiration in Cell membrane
Cellular Respiration in Mitochondria
Locomotion Rotating flagella
Undulating flagella,cilia, amoeboidmovement
Ribosome incytoplasm
Ribosome inorganelles
15
CELL CHARACTERISTICSProkaryote Eukaryote
Chromosome Single circular
ChromosomePaired linear
Chromosome locationNucleoid(no membrane)
Chromosome locationNucleus(membrane present)
Nucleolus Absent Nucleolus Present
Extra chromosomalDNA in Plasmid
Extra chromosomalDNA in Mitochondriaand Chloroplast
Cellular Respiration in Cell membrane
Cellular Respiration in Mitochondria
Locomotion Rotating flagella
Undulating flagella,cilia, amoeboidmovement
Ribosome incytoplasm
Ribosome inorganelles
16
CELL CHARACTERISTICSProkaryote Eukaryote
Chromosome Single circular
ChromosomePaired linear
Chromosome locationNucleoid(no membrane)
Chromosome locationNucleus(membrane present)
Nucleolus Absent Nucleolus Present
Extra chromosomalDNA in Plasmid
Extra chromosomalDNA in Mitochondriaand Chloroplast
Cellular Respiration in Cell membrane
Cellular Respiration in Mitochondria
Locomotion Rotating flagella
Undulating flagella,cilia, amoeboidmovement
Ribosome incytoplasm
Ribosome inorganelles
17
CELL CHARACTERISTICSProkaryote Eukaryote
Chromosome Single circular
ChromosomePaired linear
Chromosome locationNucleoid(no membrane)
Chromosome locationNucleus(membrane present)
Nucleolus Absent Nucleolus Present
Extra chromosomalDNA in Plasmid
Extra chromosomalDNA in Mitochondriaand Chloroplast
Cellular Respiration in Cell membrane
Cellular Respiration in Mitochondria
Locomotion Rotating flagella
Undulating flagella,cilia, amoeboidmovement
Ribosome incytoplasm
Ribosome inorganelles
18
CELL CHARACTERISTICSProkaryote Eukaryote
Chromosome Single circular
ChromosomePaired linear
Chromosome locationNucleoid(no membrane)
Chromosome locationNucleus(membrane present)
Nucleolus Absent Nucleolus Present
Extra chromosomalDNA in Plasmid
Extra chromosomalDNA in Mitochondriaand Chloroplast
Cellular Respiration in Cell membrane
Cellular Respiration in Mitochondria
Locomotion Rotating flagella
Undulating flagella,cilia, amoeboidmovement
Ribosome incytoplasm
Ribosome inorganelles
19
CELL CHARACTERISTICSProkaryote Eukaryote
Chromosome Single circular
ChromosomePaired linear
Chromosome locationNucleoid(no membrane)
Chromosome locationNucleus(membrane present)
Nucleolus Absent Nucleolus Present
Extra chromosomalDNA in Plasmid
Extra chromosomalDNA in Mitochondriaand Chloroplast
Cellular Respiration in Cell membrane
Cellular Respiration in Mitochondria
Locomotion Rotating flagella
Undulating flagella,cilia, amoeboidmovement
Ribosome incytoplasm
Ribosome inorganelles
20
CELL CHARACTERISTICSProkaryote Eukaryote
Chromosome Single circular
ChromosomePaired linear
Chromosome locationNucleoid(no membrane)
Chromosome locationNucleus(membrane present)
Nucleolus Absent Nucleolus Present
Extra chromosomalDNA in Plasmid
Extra chromosomalDNA in Mitochondriaand Chloroplast
Cellular Respiration in Cell membrane
Cellular Respiration in Mitochondria
Locomotion Rotating flagella
Undulating flagella,cilia, amoeboidmovement
Ribosome incytoplasm
Ribosome inorganelles
21
CELL CHARACTERISTICSProkaryote Eukaryote
Chromosome Single circular
ChromosomePaired linear
Chromosome locationNucleoid(no membrane)
Chromosome locationNucleus(membrane present)
Nucleolus Absent Nucleolus Present
Extra chromosomalDNA in Plasmid
Extra chromosomalDNA in Mitochondriaand Chloroplast
Cellular Respiration in Cell membrane
Cellular Respiration in Mitochondria
Locomotion Rotating flagella
Undulating flagella,cilia, amoeboidmovement
Ribosome incytoplasm
Ribosome inorganelles
BACTERIAL SHAPE
23
BACTERIA SHAPE
range in size from 0.20 to 2.0 micrometers in diameter1) Bacillus2) Spiral3) Cocci
24
BACILLUS
1) Bacillus Rod shape
Diplobacilli Two bacilli together
Streptobacilli Chains of bacilli
Vibrioscurved rods
25
BACILLUSEscherichia coli
26
SPIRAL
2) Spiral spirillia
Spiral, helical, corkscrew shape that is rigidrigid
spirochetethe organism is flexibleflexible and
undulating
27
COCCI
3) Coccispherical shaped
diplococciremain in pairs
streptococcichains
staphylococciclusters
28
COCCI
Moraxella catarrhallis
inhabitant of the upper respiratory tract, especially the nasal cavity
notice some are in the diploid state
BACTERIALCELL WALL
30
CELL MEMBRANE
phospholipid bilayer integral and peripheral proteins
embeddedmaintains the selective
permeability of the cellhas respiratory enzymes
31
CELL WALLcell wall surrounds the cell membraneStructurally, the wall is necessary for
1) maintain shape2) counter osmotic pressures3) attachment sites for
bacteriophages4) platform for surface appendages
32
CELL WALL1) Maintaining the cell's
characteristic shapethe rigid wall compensates for the flexibility of the phospholipid membrane and keeps the cell from assuming a spherical shape
33
CELL WALL2) Countering the
effects of osmotic pressurethe strength of the wall is responsible for keeping the cell from bursting when the intracellular osmolarity is much greater than the extracellular osmolarity
34
CELL WALL3) Providing
attachment sites for bacteriophagesteichoic acids attached to the outer surface of the wall are like landing pads for viruses that infect bacteria
35
CELL WALL4) Providing a rigid platform for
surface appendagesflagella, fimbriae, and pili all emanate from the wall and extend beyond it
36
CELL WALLcell walls of all bacteria are not identicalcell wall composition is one of the most
important factors in bacterial species analysis and differentiation
clinicallycontributes to ability to cause diseasesite of action of antibiotics
There are two major types of walls: Gram-positive Gram-negative
37
GRAM POSITIVE
Has a thick peptidoglycan layer90% of the Gram-positive cell
wall is comprised of peptidoglycan
two types of teichoic acidsteichoic acids
38
GRAM POSITIVE1) Lipoteichoic acid
on the surface, embedded in the peptidoglycan layer
linked to the cytoplasmic membrane
39
GRAM POSITIVE
2) Wall teichoic acid on the surface linked to only the peptidoglycan
layer
40
GRAM POSITIVE
41
cell wall of Gram-negative bacteria is much thinnercomprised of only 20%
peptidoglycanhave two unique regions which
surround the outer plasma membrane: periplasmic space lipopolysaccharide layer
GRAM NEGATIVE
42
GRAM NEGATIVE
a thin peptidoglycan layer an outer membrane attached to the
peptidoglycan layer by lipoproteins
43
GRAM NEGATIVE
the outer membrane is made of protein, phospholipid and lipopolysaccharidethe lipid portion is embedded in
the phospholipidThe lipid is toxic
44
GRAM NEGATIVE
The cell wall has channels called Porins for the transport of low molecular weight substances
45
GRAM NEGATIVE
periplasmic space between the cytoplasmic membrane and the cell wall hydrolytic enzymesantibiotic inactivating enzymes
transport proteins
46
Strong negative charge assists in:evading phagocytosisevade the complement system
provides increased barrier to:antibiotics, lysozymes,
detergents
GRAM NEGATIVE
47
provides more attachment sites for:virusharmful substances
more susceptible to mechanical breakage
lipid A endotoxin is toxic to host
GRAM NEGATIVE
48
CELL WALLthe cell wall is not a
regulatory structure like the cell membrane
though it is porous, it is not selectively permeable and will let anything pass that can fit through its gaps
49
EXTRACELLULAR MATRIX
attached to the cell wall made of polysaccharide or
polypeptide, or a combination of both
form a viscous layercapsuleslime layer
50
CAPSULECapsule
thick, structured and adheres strongly to the cell wallAdhere to surfaces to form coloniesAntiphagocyticAntigenicProtect the organism from dehydration
51
CAPSULE
52
SLIME LAYERSlime layer
disorganized and loosely attached to the cell wallStaphylococcus mutans
causes dental caries
53
MOVEMENTFlagellum
Made of the protein flagellinrotation is for swimming towards an
attractantwater is as viscous as syrup for a bacteriaable to move 50 microns/sec
100X bacterial body length/secfish able to swim only 10X body length/sec
54
MOVEMENTAxial Filaments
found in Spirochetes similar to flagellaattached throughout the body
length
55
PILImade of the protein pilin virulence factors project from the cell surfaceConjugation Pili
for the transfer of extrachromosomal DNA between donor and recipient
56
FIMBRIAE
used for attachment to surfacesmore numerous than pili
57
CYTOPLASMIC STRUCTURESNucleoid
area of concentrated DNA
no nuclear membrane
The DNA is single circular
double stranded without proteins
58
CYTOPLASMIC STRUCTURESRibosomes
cytoplasmic, not attached to organelles
Plasmids Extrachromosomal loops of DNA
some code for drug resistancetoxins
59
TYPICAL BACTERIA
60
ENDOSPORES
Metabolically inactivemay produce endospores under
environmental stresslack of waterlack of nutrients severe temperature changes
Clostridium Bacillus
61
ENDOSPORESSpores can be dormant for many
yearscan survive
extreme heatdesiccationradiationtoxic chemicals
62
ENDOSPORES
when conditions become favorable they revert to an active state
Spore germination is activated by heat in the presence of moistures
END CELL BIOLOGY OF
BACTERIA