1. You Make Me Sick! Bacteria and Viruses

2. Bacteria  Oldest living organisms  Microscopic prokaryotes  Bacteria=prokaryotes,prokaryotes=bac teria  Previously called Kingdom Monera 2 New Domains for Bacteria  Archaea and Eubacteria

3. Overview Cell Structure StructureFunction Cell WallProtects and gives shape Outer Membrane Protects against antibodies (Gram Neg. Only) Cell Membrane Regulates movement of materials, contains enzymes important to cellular respiration CytoplasmContains DNA, ribosomes, essential compounds ChromosomeCarries genetic information PlasmidContains some genes obtained through recomb. Capsule & Slime Layer Protects the cell and assist in attaching cell to other surfaces EndosporeProtects cell against harsh environments PilusAssists the cell in attaching to other surfaces FlagellumMoves the cell

4. Archaea  Live in extreme conditions  Most similar to eukaryotes

5. Types of Archaea Methanogens: Harvest energy by converting H 2 and CO 2 into methane gas  Anaerobic, live in intestinal tracts Extreme halophiles: Salt loving, live in Great Salt Lake, and Dead sea. Thermoacidophiles: Live in acid environments and high temps.  Hot Springs, volcanic vents

6. Eubacteria  Found everywhere else  Most common  Commonly called germs

7. Classification of Bacteria Shape  Bacillus-rod shaped  Coccus- sphere shaped  Spirillum-spirial shaped

8. Classification of Bacteria Obtaining Energy & Nutrients  Photoautotrophs-use photosynthesis  Major component of plankton  Produce large % of oxygen  Ex:cynanobacteria  Chemoautotrophs- inorganic materials  Use sulfur, nitrogen, or simple organic compounds

9. Classification of Bacteria Obtaining Energy and Nutrients(con’t)  Heterotrophs (most prokarytoes)  Dead organisms,parasites, or pathogens

10. Classification of Bacteria  Gram Stain  Produced by peptidoglycan in cell wall  Gram-positive retain stain and appear purple  Have thicker layer in cell wall.  Gram-negative do not retain stain and appear pink stain instead.

11. Gram Staining

12. Reproduction Binary Fission  Asexual reproduction  1 cell divides into 2 cells  Usually identical  Genetic mutations produce new forms of bacteria  Plamids-extra loops of DNA

13. Binary Fission  Step 1: DNA is copied and Cell grows

14. Binary Fission  Step 2:Cytoplasm and Cell Divide

15. Genetic Recombination Allows bacteria to obtain new genetic material 1.Conjugation-bacteria exchange genetic material 2.Transformation-receive DNA from the environment 3.Transduction-DNA transferred by a virus

16. Genetic Recombination CharacteristicTransformationConjugationTransduction Method of DNA Transfer Across cell wall and cell membrane of recepient Through a conjugation bridge between two cells By a virus Plasmid transfer Yes Not likely Chromosome transfer NoSometimesNo Antibiotic resistance acquired Yes Sometimes

17. Conjugation

18. Transformation

19. Transduction

20. Survival  Endospores  Produced under harsh conditions  Forms inside bacteria  Resistant to radiation,extreme temperature, lack of oxygen,etc

21. Bacterial Diseases Bacteria cause disease by…  Producing toxins  Toxin-poisonous chemical  Released or stored in bacteria  Ex:Colstridium botulinum  Destroying body tissues  Enzymes break down host tissues  Ex: Tuberculosis, and Sreptococcus  Treatment- antibiotics

22. Bacterial Diseases Antibiotic Resistance Bacteria’s ability to tolerate anitbiotics  Antibiotic-inhibit the growth or kill bacteria Plasmids usually transmit genes for antibiotic resistance. Caused by over use of antibiotics

23. Viruses

24. Viruses are not alive because….. 1.Not made of cells 2.Do not grow 3. Do not maintain homeostasis 4.Do not reproduce on their own But they do have a major impact on the living world

25. Structure of Viruses All viruses have a:  nucleic acid  Capsid  Optional Structures  Envelope  Tail fibers

26. Viral Nucleic Acids DNA Virus  Contain DNA only  Ex:herpes virus RNA Virus  Contain RNA only  Retroviruses turn RNA to DNA,then replicate  Ex:HIV

27. Capsid & Envelope Capsid  Made of protein  Encloses genetic material  Proteins match the host cells  Come in a variety of shapes Envelope  Membrane surrounding capsid  Made of proteins, lipids,and glycoproteins  Receptors help virus enter cell

28. Tail Fibers Bacteriophages  Viruses that infect bacteria  Tail and tail fibers used like a syringe  Inject viral DNA into cell

29. Reproduction Lytic Life Cycle 1.virus attaches to cell and injects DNA 2.use host cells organelles to make viral DNA and proteins. 3.New viruses are assembled in host cell. 4. Host cell breaks open and releases new viruses. 5. New viruses infect new cells.

30. Reproduction Lytic Life Cycle (con’t) Host cells die Virulent virus use lytic cycle Ex: HIV, Rabies, etc

31. Reproduction Lysogenic Life Cycle 1.Viral DNA become part of the host cells DNA. (becomes a prophage) 2.Viral DNA replicates with host cells DNA 3.Replicated host cell contain viral DNA (becomes a provirus) 4.Host cell does not die

32. Reproduction Lysogenic Life Cycle (con’t)  Temperate viruses may enter lytic cycle  Provirus may become a permanent part of the hosts DNA  Ex:chickenpox

33. Lytic & Lysogenic Cycles

34. Viral Diseases  Causes disease in bacteria,plants, and animals  Viruses are specific to their hosts  Symptoms are caused by…  Toxic parts (envelope)  Cause cell to produce toxins  Lysis of host cell  Results in fever and body aches

35. Viral Diseases  Possible causes of cancer  HPV (cervical cancer)  Hepatitis B (liver cancer)  No treatment for viral diseases only the symptoms Prevention  Vaccines- weakened form of the pathogen

36. Emergent Diseases  Newly recognized diseases or diseases that have reemerged  New Diseases  Swine Flu, Avain Flu, SARS,etc  Re-emergent  Measles, Hanata Virus, Drug Resistant TB

37. Disease Transmission  Direct Contact-kissing,sex,etc  Fomites (indirect contact)-door knobs,keyboards,etc  Droplet- sneezing, coughing  Airborne- droplets or dust  Vector- animals like mosquitoes, rats, dogs,etc

38. Important Scientists  3 scientists made major breakthrough in the fight against disease and infections.  Alexander Fleming  Louis Pasteur  Robert Koch

39. Important Scientists  Alexander Fleming is credited for his discovery of penicillin, a very important antibiotic.  Louis Pasteur is credited for developing sterilization techniques to help kill pathogens.  Robert Koch is credited for developing steps to diagnose diseases.

40. Identifying Pathogens Koch’s Postulates 1.Find and Isolate pathogen from diseased animal or person. 2.Grow pathogen in a lab. 3.Infect a healthy animal. 4.Isolate the pathogen from second animal.