BACTERIA

*Aerobic Photoautotrophs
          - rely on sunlight as a source of energy and CO2 as a source of carbon
          - primary producers
     *Cyanobacteria
          -blue-green bacteria (blue-green algae)
          - with chlorophyll a + bluish pigment
          - like plants (photosynthesis)
          - supplied O2 to premedial Earth
     *Nitrogen Fixers
          - fixation of atmospheric nitrogen
          - develop heterocysts

*Anaerobic Photoautotrophs
          - lack the key light-trapping pigment of plants, chlorophyll a anb b
          - with bacteriochlorophylls
          - purple and green bacteria
          - rely on hydrogen sulfide or H2 gas instead of H2O
          - don't produce O2

*Chemoheterotrophs
     *disease-causing bacteria
          - pathogens
     *decomposers
          - produce enzymes that breakdown organic compounds
     *fermenters

*Commercially Important Bacteria
          - used to address environmental problems
     ex: pseudomonads

ARCHAEA

Reproduction
     Asexual
          - binary fission
          - endospore
     Sexual
          - conjugation

Types

Methanogens
     - oxygen free habitats
     - produce methane gas
     - extract energy from hydrogen gas and carbon dioxide
     - in bogs, deep soil, mud bottoms of lakes
     - reminants expel CH4


Extreme Halophiles
     - extra high salt contents
     - with unique glycoproteins
     - accumulate K ions and keep out Na ions
     - generate energy by aerobic respiration
     - use bacteriorhodopsin to perform photosynthesis
     - carry carotenoids for UV protection

Extreme Thermoacidophile
     - hot and acidic water
     - sulfur-rich hot springs, hydrothermal vents (110 C)
     - obligate anaerobes
     - uses S instead of O2

PROKARYOTES II

Bacteria
     - membranes contain unbranched fatty acids
     - cell wall contains peptidoglycan
Gram +
     - thick layer of peptidoglycan
     - penicillin
Gram -
     - thin layer
     - streptomycin or tetracyline

Archaea
     - membranes have branched isoprene chains
     - for extreme conditions
     - cel wall contain no peptidoglycan

SIMILARITIES
     - cellular
     - DNA and RNA
     - manufacture their own enzymes
     - genetic material found in cytosol
     - no mitochondrion, ER, Golgi bodies, lysosomes
     - some produce capsule
     - offer protection against defense cells
     - pili - for attachment
          - hairlike structures

PROKARYOTES I

Prokaryotes
     - bacteria
     - archaea

     - cellular
     - DNA and RNA
     - ribosomes
     - don't host
     - well-coordinated system of enzymes

Size
     - small
     - Thiomargarita namibiensis
          - biggest prokaryote
          - "sulfur pearl of Namibia"

Shape and Arrangement of Cells

Cocci - spherical prokaryotes
Bacilli - rod-shaped prokaryotes
Spirilla - spiral

Infectious Particles

Viroids
     - naked, single stranded RNA
     - cadang-cadang, spindle tuber disease

Prions
     - protein particles
     - brain diseases
          - mad cow disease
          - Creutzfeldt Jacob disease
          - scrapie
          - kuru

VIRUS

Virus
          - particles smaller than cells
          - noncellular
          - specific
          - DNA or RNA
Martinus Beijerinck
         - first to use the term virus


STRUCTURE
     - capsid- protein surrounding the DNA or RNA
     - bacteriophages - virus infecting bacteria

DNA viruses
          - hepa B, smallpox, cowpox, herpes
RNA viruses
          - AIDS, mumps, common colds, leukemia, measles

TAXONOMY

Taxonomy
         - science of naming, classifying, and identifying organisms
         - systematics

Levels of Classification (taxa)

     1. Kingdom          4. Order      7. Species
     2. Phylum             5. Family
     3. Class                 6. Genus

Phylogeny
          - natural system of classification that is based on the evolutionary history or genealogy shared by a group of organisms.

Phylogenetic Trees
         - show how related organisms evolved from common ancestors
Method:
     Cladistics
           - involves identifying shared derived traits

Carolus Linnaeus
     - binomial nomenclature
genus

• tells more about the organism
• always capitalized

species

• lower case

Genus and species form the scientific name.  It is either italicized or underlined.

Aristotle
          - father of animal classification
          - land, air, water
          - "species", belonging to the same kind

Artificial Systems
         - took into account only a few characteristics
         - Aristotle and Carolus Linnaeus