Bacteria are ______ celled organisms that live everywhere. They are the oldest life forms on Earth. ______________ is the most studied bacterium. All bacteria are __________________ meaning they have no true nucleus (they do still have genetic material). Bacteria do contain ____________ _____________ containing acids & sugars that provide support as well as a cell membrane inside of this cell wall. Some antibiotics work by attacking this structure.
KINGDOM EUBACTERIA � no membrane-bound organelles, nutrition by absorption (some are photosynthetic or chemosynthetic), reproduce by __________ or ______________. Eight groups:
1. __________________ - photosynthetic � have a gooey, deeply pigmented covering � common on land & in the ocean � probably ancestors of chloroplasts in some kinds of protists � ex. =
2. __________________ - ancient � grow without sunlight or other organisms � derive energy from reduced gases (ammonia, methane, hydrogen sulfide) � play critical roles in the nitrogen cycle � ex.=
3. __________________ - rigid, rod-shaped, heterotrophic bacteria � aerobic- have flagella � responsible for many diseases � ex. =
4. __________________ - straight or curved rods w/ flagella at 1 end � very common in soil � many are plant pathogens � ex. =
5. __________________ - long, spiral cells � flagella at each end � responsible for many diseases � ex. =
6. __________________ - filamentous bacteria � often mistaken for fungi � spore-producing � sources of antibiotics � ex. =
7. __________________ - obligate parasites � ex. =
8. __________________ - long-rod-shaped bacteria � secrete slimy polysaccharides � live mainly in soil � ex. =
KINGDOM ARCHAEBACTERIA � anaerobic & aerobic bacteria adapted to environments with extreme temps, acidity, or salt content; differ from eubacteria in structure of cell wall & cell membrane � RNA polymerase & ribosomal protein very similar to eukaryotes (believed to be more closely related to eukaryotes than eubacteria) � asexual reproduction only � Three groups:
1. _______________________ - anaerobic methane producers � use CO2 as carbon source � found in soil, swamps, & digestive tracts (especially cattle) � produce nearly 2 billion tons of methane gas annually
2. _______________________ - inhabit very hot environments that are often very acidic � require sulfur � nearly all are anaerobes � ex. =
3. _______________________ - live in high salt content environments � nearly all are aerobic � all are gram-negative
Bacteria come in 3 primary shapes
1. _________________ - sphere-shaped
2. _________________ - rod-shaped
3. _________________ - corkscrew-shaped
Bacteria may also be classified based on their shapes in a group. These include
1. ___________________ - found in pairs
2. ___________________ - found in clusters
3. ___________________ - found in chains