1. Chapter 20 Bacteria & Viruses

2. Germ Theory Discovery that microorganisms are PATHOGENS (disease causing agents) The germ theory of disease states that some diseases are caused by microorganisms. These small organisms, too small to see without magnification, invade humans, animals, and other living hosts. Their growth and reproduction within their hosts can cause a disease.

4. I. Bacteria Are ________________________-lack a nucleus and have few organelles Much smaller than eukaryotes Eubacteria-larger kingdom than archaebacteria;usually have protective cell wall and determines shape Prokaryotes

5. __________________________-not such a strong,if any,cell wall,DNA sequences more like eukaryotes;live in HARSH environments like hot springs or volcanic vents Archaebacteria

6. Identifying bacteria: –by shape 1) rod-shaped are __________________ 2) spiral-shaped are_______________________ 3) spherical-shaped are cocci(coccus- singular) Bacillus or bacilli Spirillus or spirilla

9. by cell walls-use Gram Staining-Gram(+) have thick_______________________walls/gram(-) have thinner walls by movement-some do not move and some have flagella peptidoglycan

11. B. Metabolic Diversity Heterotrophs –_____________________-must take in organic molecules for energy and supply of Carbon-as do we –_____________- Autotrophs –____________________- –______________-as those found in volcanic vents Chemoheterotrophs photoheterotrophs photoautotrophs chemoautotrophs

12. Releasing Energy –1) Obligate aerobes-need constant supply of O2 –2) _______________________-do not need O2 –3) Faculatative anerobes-can survive w/or w/o O2-example-E.coli Obligate anaerobes

13. C. Growth and Reproduction _________________________grows,replicates DNA and splits in half Binary fission

14. ________________________-exchange genetic info w/ a “bridge” conjugation

15. Some produce_________________________, which can lie dormant and germinate spores

16. D. Importance of Bacteria Decomposers N-fixers-for plants Human uses-food production ;cleaning up oil spills Assist digestion

17. II. Viruses-particles of nucleic acids,protein and sometimes lipids

18. Not living-reproduce only by infecting living cells Usually has a DNA or RNA core w/outer protein coat Outer protein coat called a ______________-which enable it to enter a host cell—often destroying host cell ________________________-viruses that infect bacteria capsid bacteriophage

19. ____________________infection-virus enters cell,makes copies,and causes cell to burst _____________________________-virus integrates DNA into DNA of host cell,and viral genetic info replicates along w/host Lytic Lysogenic

22. _______________________________- contain RNA as genetic info and produce DNA copy of RNA retroviruses

23. III. Diseases Bacterial –Infect by damaging cells or releasing toxins –Mycobacterium tuberculosis –Streptococcus –Cornyebacterium diptherae –Anthrax –Lyme’s disease –Tetanus –Meningitis –Tooth decay prevention –-_______________________preparation of weakened or killed pathogens –________________________-compounds that block the reproduction or growth of bacteria vaccination antibiotic

24. 2)control- sterilization,heat,disinfectantants,proper food processing and storage

25. B. Viral Common cold Influenza Smallpox Warts AIDS Chickenpox Measles Hepatitis A,B, or C West Nile Polio

26. –________________________________single- stranded RNA moleculesw/no capsid-attack plants –______________________-virus –like particles of protein-may cause protein clumps that induce new prions---example-Mad Cow Disease viroids prions