1. Viruses

2. What is a pathogen? Agent of disease Bacteria Viruses Fungi
Environmental Substances

3. What is a Virus? Nucleic Acids Proteins Sometimes Lipids DNA RNA
Capsid- protein coat
Sometimes Lipids

4. Viral Infections
Lytic- virus injects cell with DNA or RNA and cell is tricked into making multiple copies of the virus, eventually there are so many viruses produces that the cell bursts and the viruses are spread to other cells

5. Viral Infections
Lysogenic cycle- virus injects cell with DNA or RNA and cell copies virus every time the cell copies itself

6. Viral Infections
Viruses may switch back and forth from Lytic to Lysogenic at any given time

7. Bacteriophages
Viruses that infect bacteria T4

8. Viral Cycles

9. Viruses in plants Tobacco Mosaic
Difficult for viruses to enter cells because of cell wall
Take advantage of damage to plant
May be spread by insects
Potato yellow dwarf virus - leafhopper

10. Viruses in Animals Foot and mouth-cattle Rabies
Oncongenic viruses (cancer causing)

11. Viruses in Humans Cold Influenza Smallpox Aids (Retrovirus-RNA)
Chickenpox
Measles
Hepatitis A,B,C
Polio
West Nile

12. Virus Treatment Typically we treat symptoms
Typically vaccines try to prevent you from getting

13. Virus Pics

14. Virus-like partials Viroids- RNA no protein
Prions- Protein no DNA or RNA – may form protein clumps in nerve tissue and disrupt its function

15. Bacteria Prokaryotes- no nucleus Two main groups
Archaebacteria- harsh environments no peptidoglycan in cell walls
Eubacteria- peptidoglycan in cell walls

16. Archaebacteria Genes like eukaryotes (nucleus) No peptidoglycan (Carb)
Harsh environments
Methanogens
Mud
Digestive tracts
Anaerobic (no oxygen)
Salt
Hot water

17. Eubacteria Peptidoglycan in cell wall Gram positive Gram negative
Purple stain- thicker cell walls
Gram negative
Pink -thinner cell walls
Which is important when it comes to antibiotics.

18. Bacteria Reproduction
Sexual
Conjugation
Asexual
Copy
Endospores
Survive rough times

19. Obtaining Energy Foldable
Photosynthesis
Chemoautotrophs
Heterotrophs
Draw and Label pic p.446

20. Photoautotrophs Grouped based on pigments they contain
Some are aerobic and some are anaerobic
Cyanobacteria
Important for fixing nitrogen
Found in lichens
May have made Oxygen in Earth’s early atmosphere

21. Chemoautotrophs Use inorganic molecules to make energy
Ammonia
Hydrogen sulfide
Methane
Important for nitrogen fixation in the roots of plants

22. Heterotrophs Category that most bacteria fall into
Some are aerobic some anaerobic
Some do nitrogen fixation
Crop rotation of legumes adds nitrogen to soil
Great importance as decomposers

23. Harmful Bacteria
Directly attacking host tissue
Releasing Toxins

24. Antibiotics Antibiotics are used to fight bacterial infections
Many antibiotics are developed from chemicals produced by fungi
Overuse of antibiotics can cause antibiotic resistance
Overuse of antibacterial soaps

25. Bacterial Uses Genetically altered to produce drugs and medicines
Used to produce chemicals for industrial use
Mining
Clean up oil spills
Food

26. Bacteria in Food Pickles Buttermilk Cheese Sauerkraut Olives Vinegar
Sourdough

27. Typical E. Coli

28. Bacterial Shapes

29. Bacterial Diseases

30. Viral Diseases Type of Virus Nucleic Acid Disease Oncogenic viruses
Retrovirus
Adenoviruses
Herpesviruses
Poxviruses
DNA
RNA
Cancer
Cancer, AIDS
Respiratory infections
Chickenpox
Smallpox

31. Virus Versus Cell

32. Sample Experiment
A student placed a disk of filter paper in each of the following solutions: disinfectant 1, disinfectant 2, disinfectant 3, and distilled water. While the four disks were soaking in their respective solutions, she streaked a sterile nutrient agar dish with a culture of E. coli bacteria. Then, she placed each disk carefully onto the nutrient agar dish, placed the lid on the dish, taped it shut, and incubated the dish at 37°C for several days. Figure 19–4 shows how the nutrient agar dish looked on Day 1 and Day 4.

33. Table

34. Questions What is the student probably trying to test?
What is the control in the experiment?
How can the student measure the effectiveness of each disinfectant?
Which disinfectant was the most effective at controlling the growth of E. coli? How do you know?