Six Kingdoms of Classification Eubacteria Archebacteria Protists Fungi Plants AnimalsCell type Prokaryotic Prokaryotic Eukaryotic Eukaryotic Eukaryotic EukaryoticNumber of Unicellular Unicellular Mostly Mostly Multicellular MulticellularCells unicellular multicellularMode of Autotroph or Autotroph or Autotroph or Heterotroph Autotroph Heterotrophnutrition heterotroph heterotroph heterotrophChemistry Made No Made of Made of Made of No cell walls.of cell walls Peptidoglycan peptidoglycan cellulose (in chitin. cellulose some).
What do we already knowabout bacteria? Small, unicellular Prokaryotic, no nucleus, not many organelles Independent, non-specialized First life on Earth
Kingdoms of Bacteria1. Eubacteria • Larger of the two kingdoms • Found in most environments • Cell wall contains carbohydrate “peptidoglycan” • Ex) E.coli – bacteria in your intestine helps with digestion
Kingdoms of Bacteria2. Archaebacteria • Cell wall lacks peptidoglycan. • Live extremely harsh environments • Ex.) Methanogens -live in animal digestive tracts (no oxygen gas).
Identifying Bacteria Bacteria can be identified by… 1. Shape and Arrangement 2. Chemical nature of cell wall 3. Gram staining 4. How they obtain energy (food)
Chemical Nature of CellWall Eubacteria identified by make-up of their cell walls. Method called Gram staining is used. Gram Positive – “thick” cell wall of peptidoglycan, purple Gram Negative – “thin” cell wall of peptidoglycan, pink or red – can NOT be treated by many antibiotics
Obtaining Energy All living things need a method for obtaining … -Energy (ATP) -Organic Compounds (Carbon)1. Heterotrophs (cannot make own food) Chemoheterotrophs- take in food for both energy and organic compounds. ex) Salmonella bacteria eat foods and release “toxins” cause food poisoning Photoheterotrophs- Use sunlight for energy and obtain food for a source of organic compounds.
Obtaining Energy (cont.)2. Autotrophs (make own food) Photoautotrophs – Use sunlight to make energy and organic compounds (glucose). These bacteria are all green (kind of like little plants). Many live on surface of ocean (cyanobacteria). Chemoautotrophs- Do not use light. Instead, use chemicals in their environment to make food and organic compounds. Live where there is no light (ocean floor).
Few Other Characterisitcs ofBacteria… Obligate aerobes- Bacteria that require a constant supply of oxygen. Ex.) Tuberculosis Obligate anaerobes- Bacteria that do not require oxygen. Ex) Bacteria causes botulism Facultative anaerobes- Can survive with or without oxygen. Can live anywhere. Ex) E.coli
Few Other Characteristicsof Bacteria… How do bacteria reproduce? Binary fission -asexual = “clones” -1st growth -2nd DNA copied -3rd splits - 2 cells
Conjugation Since binary fission results in clones, bacteria need a way to gain variety. They do this through exchanging DNA in a process called “conjugation.” Genetic material exchanged; allows bacteria obtain new traits = antibiotic resistance Sometimes called “transformation.”