1. Viruses/Bacteria

2. Virus Link between living and non-living Not cells “Biological Particle” Needs host

3. Parts of Virus Seen with electron microscope Capsid –Protein covering –95% of weight of virus Nucleic acid –DNA or RNA Sheath –Identification Basal plate Tail fibers –attachment Envelope –Outer covering

4. Example of Viruses Ebola*HIV Influenza (flu)*Polio Mono*Meningitis SARS*Bird Flu West Nile*Norwalk Virus Hantavirus*Chicken Pox Shingles*Lassa Fever Herpies Simplex I

5. Classification of Viruses Composition (DNA or RNA) Structure (T-4, envelope, helical) Type of disease it causes Kind of host cell it infects (bacterial, human, fungal)

6. How Viruses are Spread Airborne Body fluids (sex, saliva, blood) Ingest

7. Life Cycle (2 Types) I.Lytic –Quick 1.Attachment Receptor site on host 2.Entry Transfer nucleic acid into host 3.Replication Viral nucleic acid takes control of host cell and produces viral parts 4.Assembly Viral parts put together by host cell 5.Release Host cell explodes (lyses), releasing viruses

8. II.Lysogenic –Longer 1.Attachment Same as lytic 2.Entry Same as lytic 3.Incorporation Virus DNA inserted into host DNA and remains undetected 4.Mitosis Cell replication copies host AND viral DNA ***ENVIRONMENTAL CUE*** 5.Replication Makes parts of virus 6.Assembly 7.Release In greater number, harder to defend against

9. Vaccine Weakened virus –Heated/treated with chemicals to damage DNA/protein covering Body recognizes foreign invader and makes antibodies to destroy it Virus DNA not functioning so body will have immunity without having disease

10. Bacteria Unicellular Prokaryotic Oldest life form (~3.5 b.y) Have a loop of DNA Found everywhere

11. Naming of Bacteria Suffix –Coccus = spherical –Bacillus = rod –Spirillum = corkscrew –Flagellated = hair-like projection Prefix –Diplo = in pairs –Strepto = in chains –Tetra = in groups of four –Staphylo = in clusters

12. Examples…

13. Features of a Bacterial Cell:

14. Reproduction Asexual –Binary fission DNA replicates, divides into 2 identical cells Not mitosis!! Why?? –Budding Small piece breaks off Sexual –Conjugation Bacteria connect at pili, DNA is exchanged, separate and undergo binary fission

15. Other Characteristics Heterotrophs and autotrophs Respiration = anaerobes, aerobes, facultative Survival = endospores –Tough, protective wall forms in harsh conditions

16. Why so Successful??? Reproduce quickly Use poisonous substance for food sources Exist in extreme conditions Mutate easily Dormant state (years) as endospore Antibiotics used to fight bacteria (“anti-”; “bios”)

17. Benefits of Bacteria Food Decomposers Medical research Digestion Eats poisons for food

18. Immune System Types of white blood cells (WBCs) I.Phagocytes –Engulf the microbe or pathogen (anything disease-causing) –Macrophage = special because after it ingests pathogen, it displays antigen (identification of virus) –Non-specific defense

19. II.Lymphocytes –Specific defense, respond to antigen A.Helper T Cells Identify bad microbe(s) and send info to other cells (uses the antigen) B.Activated B Cells Make antibodies (specific to virus, surround virus and inactivate it) C.Killer T Cells Kill body (host) cells that are infected D.Suppressor T Cells Call off attack, shut down immune response E.Memory Cells Remember virus