Download Archaebacteria and Eubacteria

Chapter 18.2
Organisms in these two kingdoms are prokaryotes
 have no membrane bound organelles
 Kingdom Archaebacteria (extremophiles)
 Usually live where there is no oxygen (anaerobic)
 3 types
 Methane-producing  live in swamps and cows
stomachs
 Salt-loving  live in lakes with a high mineral content
 Acid and Heat-loving  live around deep ocean vents
with temps above 100 OC
Kingdom Eubacteria (true bacteria)
 Heterotrophic  use organic molecules as a food source
 Some are parasites obtaining nutrition from living organisms
 Some are saprophytes obtaining nutrition from dead organisms
and organic waste (poop)
 Photosynthetic autotroph  cyanobacteria
 Produce chemical energy through photosynthesis
 Chemosynthetic autotroph
 Break down and release energy from compounds containing
sulfur or nitrogen
 Called chemosynthesis
General Structure of a Bacterium
 Contain very small ribosomes
 Single circular chromosome
 Cell wall  prevents bacteria from bursting
 Capsule  a sticky gelatinous layer outside
of the cell wall
 Flagellum  a whip-like projection that
help the bacterium move
 Pilus  air-like structures coming out the
cell surface, help bacteria stick to surfaces
 Plasmid  a few genes in a circular
chromosome
Life of a Bacterium
 Most bacteria live in an environment where there
is more water outside than inside so water is
always trying to get in
 As long as the cell wall is intact, bacteria will still survive
 Antibiotics and plain old soap cause holes to develop in
the cell wall causing the bacteria to burst (die)
Identifying bacteria
 Gram stain  shows differences in
cell wall structure
 Gram positive  stain purple
 Gram negative  stain pink
 Shape
 Cocci  sphere
 Bacillus  rod
 Spirilli  spiral
 Growth patterns
 Diplo  pairs
 Staphylo  grape-like clusters
 Strepto  long chain
Reproduction
 Binary fission  a form of asexual
reproduction that produces identical
offspring
 Some bacteria can reproduce every 20
minutes in ideal conditions
 Conjugation  a form of sexual
reproduction where on bacteria transfers
it chromosome to another through a
pilus
 Creates genetic diversity
Bacterial diversity
 Metabolism
 Obligate aerobes  require oxygen to respire
 Obligate anaerobes  die in the presence of
oxygen
 Survival
 Some bacteria form a tough outer layer called
an endospore that allows them to survive
when water is scarce
How are bacteria helpful and
harmful?
 Some bacteria fix nitrogen into a
form that plants can use
 Recycle nutrients
 Used to make food and medicine
 Cheese, yogurt, some antibiotics
 Can cause disease
 Anthrax, tuberculosis, cavities, strep
throat