PROKARYOTES *include bacteria and archaea *singular: bacterium / plural: bacteria PROPERTIES 1. Bacteria are classified into two kingdoms: Eubacteria (true bacteria) and Archaebacteria (Ancient Bacteria). 2. Bacteria are the MOST NUMEROUS ORGANISMS ON EARTH. 3. Organisms are classified as Bacteria by one characteristic: the lack of a cell nucleus (the name "prokaryote" means "before a nucleus") 4. Outer cell wall made of petidoglycan 5. Some move by means of a flagella (sing. flagellum) 6. Fimbrae - fibers that stick to surfaces (tooth decay, gonorrhea) 7. Region called the NUCLEOID which has a single circular chromosome, accessory rings of DNA called PLASMIDS REPRODUCTION Occurs by BINARY FISSION (mitosis) and CONJUGATION (exchange of DNA) TRANSFORMATION- bacteria incorporate genes from dead bacteria TRANSDUCTION - viruses insert new genes into bacterial cells. This method is used in biotechnology to create bacteria that produce valuable products such as insulin ENDOSPORES - during unfavorable conditions, bacteria enclosed in a protective coat (Ex. Tetanus NUTRITION & NEEDS Obligate anaerobes - cannot grow in the presence of oxygen Facultative anaerobes - can grow with or without oxygen Aerobic - require oxygen Photoautotrophs - photosynthetic Chemoautotrophs - obtain energy from oxidizing inorganic compounds, such as ammonia Chemoheterotrophs - decomposers
Bacterial Structure Shape of Bacteria/ Naming Cocci - sphere Bacilli - rods Spirilla - spirals Staph - in clusters Strep - in chains Ex. Staphylococcus Gram Stain Gram's Stain is a widely used method of staining bacteria as an aid to their identification. It was originally devised by Hans Christian Joachim Gram, a Danish doctor. Gram's stain differentiates between two major cell wall types. Bacterial species with walls containing small amounts of peptidoglycan are GramnegativeBacteria with walls containing relatively large amounts of peptidoglycan are Gram-positive.
Gram Negative -- light red or pink color Gram Positive -- dark purple Escherichia coli, Salmonella typhi, Vibrio cholerae and Bordetella pertussis Staphylococcus epidermidis, Streptococcus pyogenes, and Clostridium tetani Not all bacteria can be stained by Gram's method, the best-known exception belong to the genus Mycobacterium which have waxy cell walls.
How Gram Stains are Made For more information on Gram Stains, see http://www-micro.msb.le.ac.uk/video/gram.html Bacteria and Health - Some diseases caused by bacteria: tetanus botulism Black Plague Tuberculosis gonorrhea syphilis Lyme disease Strep throat Pneumonia Anthrax necrotizing fasciitis (flesh eating bacteria) toxic shock syndrome The Usual Suspects *these are the names of specific bacteria you need to know and the diseases they cause Streptococcus lactis Staphylococcus aureas Bacillus subtilis strep throat, related bacteria causes necrotizing fasciitis found on skin, responsible for minor infections (like on cuts/scratches) common lab bacteria, easy to grow, unharmful
Bacillus tetani Bacillus botulism Bacillus pestis Bacillus anthracis Mycoplasmas Rickettsia rickettsi Escherichia coli causes tetanus (lockjaw) causes botulism (food poisoning) causes Black Plague anthrax very very tiny, cause of pneumonia link between bacteria and viruses, can't reproduce outside host, causes Rocky Mountain Spotted Fever E. Coli - common bacteria of the digestive tract, also causes food poisoning Antibiotics and Antiseptics Joseph Lister created the first antiseptic, an acid to spray on tables and instruments before surgery (1860) The Discovery of Penicillin Alexander Fleming Noticed mold growing on petri dishes Bacteria did not grow where the mold was He isolated the chemical that killed bacteria, but it was not stable Howard Flory continued the work, later stabilized the chemical Fleming and Flory received the Nobel Prize in 1945