1. er
Bacteria & Viruses
pg 471

2. Bacteria Eubacteria Archaebacteria Prokaryotes Prokaryotes
Cell walls w peptido glycan
Prokaryotes
Cell walls w/o peptidoglycan
pg 472

3. Identify bacteria Shape Cell walls Movement
Energy – where does it originate? pp

4. Shape
Bacilli - rod
Cocci - sphere
Spirilla - spiral, corkscrew

5. IMPORTANCE OF BACTERIA
Decomposers
Nitrogen fixation
Human use
Industrial, pharmaceuticals, research
Our intestines E. coli or Escherichia coli
We give: shelter, warm, food supply
They give: help with processing foods, make vitamins Pp

6. Control bacterial growth
Sterile heat
Disinfectants – kitchen, bathroom, anti-bacterial soaps (not necessarily a good idea)
Food storage & processing
Refrigeration
Cooking food
Canning
Chemically preserved (salt, vinegar, sugar) honey: nature’s antibacterial pp

7. Viruses Very small, diverse group
Living or not living (figure 19-11) ?
pp 478, 483

8. Virus parts Two main parts: genetic material and protein coat
Genetic material = DNA or RNA
Protein coat = capsid
T4 Bacteriophage
Tobacco MosaicVirus
Influenza Virus
RNA
head
DNA
RNA
Capsid
Capsid
Proteins
Tail
sheath
Tail
fiber
Surface
proteins
Membrane
envelope pp

9. Capsid proteins Allow virus to enter host cell
Capsid binds to receptors on host cell to “trick” the cell into letting it enter
Viruses are highly specific to host cell
Plant viruses infect plants
bacteriopahges infect bacteria (bacterio = bacteria, phage = eats)
Most of the time animal viruses are species specific
pg 479

10. Virus Life cycle Lytic and Lysogenic Cycles
Symbiotic relationship? pp

11. Retrovirus Retro = backwards, backwards virus Genetic material = RNA
Mutates more frequently
Infects RNA DNA DNA like prophage (dormant)
Examples: some cancers, HIV
pg 483