BACTERIA Unit 6. Classified by: Respiration: anaerobes - cannot survive in the presence of...
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Transcript of BACTERIA Unit 6. Classified by: Respiration: anaerobes - cannot survive in the presence of...
BACTERIAUnit 6
Classified by:Respiration:
anaerobes - cannot survive in the presence of atmospheric oxygen.
aerobes - cannot survive without atmospheric oxygen.
O2
O2
Classified by:Shape:
Cocci - round bacterial cells.
Bacilli - rod-shaped bacterial cells.
Spirilli - spiral-shaped bacterial cells.
Classified by: Clustering:
diplo - a prefix used with the shape name to indicate pairing of cells.
strepto - a prefix used with the shape name to indicate filaments/strip
staphylo - a prefix used with the shape name to indicate clusters.
For Review….A. BacilliB. CocciC. Spirilli
For Review….A. StreptobacillusB. StreptococcusC. DiplobacillusD. DiplococcusE. Staphylococcus
Parts of a Bacterial Cell Cell wall - some rigid and others flexible. Cell membrane - same as other cells. Cytoplasm - same as other cells. DNA - a single, circular chromosome located in the
cytoplasm.. Capsule - a thick, gel-like,
protective coating on some bacteria cells.
Pilli - short, hair like protein structures on the surface of some bacteria that help them stick to host cells.
Flagella - long protein structures that turn to propel some bacteria cells.
Nutrition Most are heterotrophic –
use food produced by other organisms. Bacteria that feed on dead or decaying
organic matter are heterotrophic bacteria called saprophytes.
Some are autotrophic - able to produce their own food. Photoautotrophs - use sunlight as a source
of energy like plants. Chemoautotrophs - use energy from
chemical reactions to make their food.
Archaebacteria
A. Methanogens: oxygen is a poison to these
bacteria, live in anaerobic conditions. they produce energy by
converting H2 and CO2 into methane gas
B. Halophiles: these "salt-loving" bacteria live in
environments with a very high salt concentration that would kill most other bacteria.
Halophiles use salt to generate ATP for energy.
Archaebacteria
C. Thermoacidophiles: live in extremely acidic
environments (pH less than 2)extremely high temperatures
(up to 110o C). live in environments like the
geothermal springs at Yellowstone National Park.
Archaebacteria
Eubacteria • contains the bacteria commonly
referred to as germs• contains most of the world's
bacteria, • 12 different phyla • live in environments ranging from
temperatures near the boiling point of water to well below the freezing point of water
Reproduction Binary fission – (asexual)
the DNA replicates and then the cell pinches inward and splits in two.
http://www.cellsalive.com/ecoli.htm Conjugation – (simple sexual
reproduction) two cells exchange a portion
of their DNA across a bridge formed between the cells.
Toxins Poisons produced by bacterial pathogens PATHOGEN = organism that produces
disease Endospores –
during adverse conditions, the DNA is encased in a protective envelope. This endospore can lie dormant for years or until favorable conditions return.
Antibiotics Antibiotics are chemicals that inhibit the
growth of some bacteria. Penicillin - interferes with cell wall
synthesis. http://www.cellsalive.com/pen.htm
Tetracycline - interferes with bacterial protein synthesis.
Many antibiotics are derived from chemicals that bacteria and fungi produce
Study antibiotic resistance (handout) and answer the following questions: What is antibiotic resistance? Why should antibiotics not be used for
most sore throats? Infer how a bacterium becomes
antibiotic resistant?
PasteurizationHeat food to a
temperature that kills a harmful bacteria
Milk, fruit juicesLouis Pasteur
developed this process for wine in 19th century
Good Bacteria Escherichia coli is a bacteria that lives in the human
intestine and aids digestion. Lactobacillus lactis
Milk to Yogurt Streptococcus diacetilactis
Milk to Sour cream Streptococcus faecalis
Milk to Cheese Leuconostoc mesenteroides
Cabbage to sauerkraut Streptococcus diacetilactis
Cucumbers to Pickle
Good Bacteria
Soil bacteria that makes streptomycin (antibiotic)
Cleans waste from sewage water at water treatment plants
Good Bacteria
Natural pest-killer in gardens and on crops
Helps crops take up nutrients from the soil
Good Bacteria Bacteria eat methane gas to clean up
hazardous waste dumps and landfills Used to clean up oil spills in ocean
They turn oil into CO2 and other harmless byproducts
Used to make wine, infant formula, chewing gum, paper, stonewashed jeans