Download v. taxonomy of the prokaryotes

PROKARYOTES
I.
GROSS MORPHOLOGY
A. Common shapes
1. Rods (bacilli, plural; bacillus, singular)
a) Cigar shaped
2. Cocci (coccus, singular)
a) Spherical shaped
3. Spirilla (spirillum, singular)
a) cork-screw shaped
B. Size
1. ~1 - 2 m on average
a) Viruses are 10 - 300 nm (0.01 to 0.3 m)
b) Eukaryotic cells are ~10 m
II. ULTRASTRUCTURE
A. The prokaryote genome
1. One circular, double-stranded DNA
a) No membrane around it, therefore, no true nucleus
b) Prokaryote = before nuclei
B. Pili
1. Used for specific attachment
a) Teeth, urogenital tract, intestines, etc.
2. Sex pili used in conjugation
C. Capsule
1. A slime secretion
2. Functions
a) Prevents phagocytosis
b) Prevents desiccation
c) Non-specific adherence
D. Plasma membrane
1. Functions
a) Retains the protoplasm
b) Selectively permeable
c) Contains respiratory chain
(1) Site of ATP production
(2) Functionally analogous to the mitochondria
d) Contains photosynthetic apparatus
(1) Functionally analogous to the chloroplast
E. Cell Wall
1. Structure
a) Made of cross-linked polysaccharides called peptidoglycan
2. Function
a) Gives cell their shape
b) Protects from stress
3. Site of action of many antibiotics
a) Penicillins, vancomycin, bacitracin, etc.
F. Ribosomes
1. Makes proteins by translation
G. Flagella
1. Not related to eukaryotic flagella
2. Taxis
a) Movement towards or away from a stimulus
III. REPRODUCTION AND GROWTH
A. Not meiosis or mitosis
1. Only one chromosome present
B. Binary fission
1. Asexual
a) All daughter cells exactly the same as mother cell
b) Daughter cells are clones of each other and the mother cell
2. Generation time ranges from 10 minutes to several days
IV. METABOLISM
A. Oxygen requirements
1. Anaerobes
a) Fermentation
(1) Produce alcohols, acids, aldehydes
2. Facultative anaerobes
a) Use oxygen for respiration if it is available, but can ferment in its absence
3. Aerobes
a) Use oxygen for respiration
B. Nutritional types
1. Phototrophs
a) Use light energy and CO2
2. Chemotrophs
a) Lithotrophs
(1) Use inorganic energy source (H2, H2S, NH2, and Fe) and CO2
b) Organotrophs
(1) Use organic compounds for both energy and carbon
V. TAXONOMY OF THE PROKARYOTES
A. Archaeobacteria
1. Methanogens
a) Methane is a green house gas
(1) Marshes and rumen of ruminants (e.g., cows)
b) Methane is a clean burning fuel
2. Extreme halophiles
a) 15 - 20% salt
3. Thermoacidophiles
a) Commonly live in areas at 80C at pH 2
b) Been found at 165C and at pH 0.2
B. Eubacteria
1. Cyanobacter
a) Oxygenic photosynthesis
2. Purple and Green phototrophic bacteria
a) Anoxygenic photosynthesis
3. Pseudomonads
a) Very versatile chemotrophs which degrades many complex organic
compounds, including some pesticides, plastics, and petroleums
(1) Demineralization
4. Spirochetes
a) Cork-screw shaped
b) Examples
(1) Treponema pallidum
(a) Causes syphilis
(2) Borrelia burgdorferi
(a) Causes Lyme disease
5. Endospore-forming bacteria
a) Form resistant endospores
b) Important in the food industry
(1) Clostridium botulinum causes botulism
c) Important in the medical field
(1) Bacillus anthracis causes anthraz
(2) C. tetani causes tetanus
(3) C. perfringes causes gas-gangrene
6. Enteric bacteria
a) Facultatively anaerobic, rod-shaped bacteria that live in the intestines of
mammals
b) Escherichia coli is used as an indicator of fecal contamination
c) Some are beneficial (vitamins, prevent pathogens from colonizing gut)
d) Some are pathogenic (Salmonella typhi and Vibrio cholera)
7. Rickettsias and Chlamydias
a) Intracellular parasites
b) Some cause Rocky Mountain spotted fever
c) Some cause nongonococcal urethritis and blindness in newborn
8. Mycoplasmas
a) Cell-wall-less bacteria that inhabit body fluids of plants and animals
9. Actinomycetes
a) Produce many useful antibiotics
(1) Especially the genus Streptomyces
VI. ENVIRONMENTAL MICROBIOLOGY
A. Important in demineralization
1. Breaking down of organic molecules into inorganic molecules
2. If a compound cannot be degraded, it is considered non-biodegradable
B. Nitrogen
1. Source of all usable nitrogen for all life forms
VII. PATHOGENIC MICROBIOLOGY
A. Most bacteria are harmless
B. To show that a bacteria causes harm, one might use Koch's postulate
1. The following criteria must be met to fulfill Koch's postulate
a) Find the same organism on each diseased individual
b) Isolate pathogen from diseased subject and grow in pure culture
c) Induce disease when pure culture is inoculated into a healthy subject
d) Isolate the same organism from the infected experimental organism