Bacteria & Viruses
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Transcript of Bacteria & Viruses
Bacteria &
Viruses
4 Ways to Identify Bacteria
1. Shape
Cocci Bacillus Spirochete
2. Cell Wall
Peptidoglycan – in bacteria cell wall
• Gram (+) Purple Gram (-) Red
3. Movement
Flagella Slime Layer None
4. How they get their energy
• Photoautotroph
• Chemoautotroph
• Heterotroph
• Photoheterotroph
Bacterial Reproduction & Growth
Binary Fission Conjugation
Nitrogen FixationProcess where bacteria on plant roots convert
nitrogen gas in the air into ammoniaNitrogen is necessary for proteins and nucleic acids
Mutualism!Both plant and bacteria benefit
Human uses for bacteria
Pathogens – Bacteria that cause disease
Two Ways Bacteria Cause Disease
• Produce Toxins (Food poisoning)
• Damage Tissue
Controlling Bacterial Growth
• Antibiotics – Slows growth; does not kill bacteria
• Disinfectants – Chemical that kills bacteria
• Sterilization – Heat, pressure, gas that kills bacteria
• Refrigeration – Slows growth; does not kill bacteria
• Canning – High heat to kill bacteria• Chemical Treatments –
Preservatives in food; slows growth; does not kill
Retroviruses
Have RNA which needs ReverseTranscriptaseto convert into DNA and then added into host DNA for replication of virus
Prions – Infectious Proteins when eaten target specific tissues such as the brainMad Cow DiseaseScrapies in Sheep