Bacteria!
Kingdom Monera
Prokaryotes
Domain Archaebacteria
Domain Eubacteria
Generally…
• Different classifications
• Very small
• Reproduce asexually – fission
• Unicellular (may live in colonies)
• Very diverse
• Prokaryotes (no cell compartments)
• Around for 3.5 billion years!
http://commons.wikimedia.org/wiki/File:Cholera_bacteria_SEM.jpg
www.darwin.nmsu.edu
What’s the difference??
Prokaryotes
Eukaryotes
cell size
~ 1 micrometer
~ 10 micrometers (varies!)
organelle membrane
lacking membranes
has internal 'compartments'
multicellular?
genetic material
singular;
may form clumps / filaments
usually multicellular
usually single circular DNA
(some RNA)
linear DNA that form
chromosomes
cell division
binary fission;
two duplicate daughter cells
mitosis with nuclear division
flagella
simple; spins;
single fiber of protein
more complex microtubules;
moves back and forth
metabolic diversity
many types anaerobic & aerobic
only aerobic
Relative size of cells and other particles…
This website has great information, including this demonstration of relative size
www.answers.com/topic/archaeon
General anatomy of a bacterium
From textbook
Reproduction
• Predominantly binary fission
• Many able to reproduce every 20
minutes (!)
• May form endospores
• Genetic recombination may
occur
– Transformation:
absorb ‘loose’ DNA
– Conjugation:
pieces of DNA swapped
– Transduction:
involves bacteriophages
From textbook
From textbook
Common shapes and classification
Coccus – sphere
Baccillus – oblong
Spirochete - coiled
May also be classified
by cell structures,
various appendages,
movement,
energy source
Wikieducator.net/biology
Gram negative or positive
Gram Positive: retain a violet dye
Gram Negative: retain pink dye
Some antibiotics work only on gram-positive or –negative bacteria
From textbook
Archaebacteria (Archaea)
• Ancient bacteria
• Developed during early Earth
– 3.5 billion years ago
– Adapted to survive in ‘extremes’
• Halophiles
• Thermoacidophiles
• Methanogens
• May be photosynthetic, autotrophs,
heterotrophs, chemosynthetic
Eubacteria (Bacteria)
• Includes some chemoautotrophs,
photoautotrophs, heterotrophs
• Cyanobacteria
• Different from Archaea:
– In DNA & RNA
– In polymerase (simpler in Eubacteria)
– Peptidoglycan present in Eubacteria cell wall
(not Archaea or Eukaryote cell walls)
Not-so-beneficial Bacteria
May impact in a variety of ways
• Clostridium botulinium – produces toxic protein; food
poisoning
• Staphylococcus aureus – produces toxic protein;
common on skin, harmful inside body
• Salmonella spp. – food poisoning & typhoid fever
Cholera
Syphilis
Anthrax
Leprosy
Bubonic Plague
Tuberculosis
Rocky Mountain
Spotted Fever
Tetanus
Diptheria
From Wikipedia
Beneficial Bacteria
•
•
•
•
Oxygen producers
Decomposers
Bioremediation
Production of food
– Lactobacillus, Lactococcus
• Pest control
– Bacillus thuringiensis
•
•
•
•
•
•
•
Digestion
Production of methane
Study of biology
Production of medicines
Nitrogen-fixing bacteria
Flashlight fish
Symbiosis with fungus
Bacteria
&
You…