1. BACTERIA, PROTISTS, FUNGI, AND VIRUSES...
PATHOGENS
BACTERIA, PROTISTS, FUNGI, AND VIRUSES...

2. PROKARYOTAE; aka Bacteria…
Prokaryotic (no nucleus)
Genetic code; one single circular strand of DNA
Plasmids are DNA outside the chromosome
No membrane bound organelles
They do have ribosomes
Cell wall made of an amino-sugar called peptidoglycan
Pili are hair like appendages on outside of the bacteria; for attachment and reproduction

3. Structure…

4. Metabolism… Most are heterotrophs Autotrophs; make their own food
Feed off dead organic matter, symbiotic, and parasitic
Autotrophs; make their own food
Photosynthetic
Chemosynthetic

5. Respiration… Obligate aerobes; need oxygen
Obligate anaerobes; oxygen kills them
Facultative anaerobes; with or without oxygen

6. REPRODUCTION Asexual = binary fission (mitosis)
Sexual = conjugation; uses pili
Can reproduce as quickly as 20 minutes

7. BACTERIA CAN EXCHANGE GENETIC MATERIAL!!!
Plasmid: giving a chunk of DNA
Conjugation: swapping DNA via “pili”

8. Transfer of DNA…
Conjugation

9. Classification by Shape
Bacillis = Rod shaped
Coccus = Spherical
Spirillum = Spiral Shaped

10. SHAPES
Coccus
Spirillum
Bacillus

11. Classified by Organization…
Strep
Staph
Diplo

12. Classified by Cell Wall Structure…
Gram Positive = Two layer membrane
Thick peptidoglycan cell wall
Plasma membrane under the cell wall
Purple
Gram Negative = Three layer membrane
Thin peptidogycan cell wall
Lipid membrane > petidoglycan cell wall > plasma membrane
Pink

13. Gram Positive vs. Gram Negative…

14. BACTERIA: THE GOOD, THE BAD, THE UGLY…
Bacteria can be pathogens…
Anthrax, tetanus, scarlet fever, strep throat…
Bacteria can be useful…
Nitrogen fixing; helps plants survive
Degrades wastes
Alternative energy sources
Produce plastics
Source of possible medicinal drugs

15. VIRUSES…

16. Characteristics… Nucleic acid core; either DNA or RNA but never both
Capsid; protein coat surrounding the nucleic acid core
No ribosomes or organelles of any kind
No metabolism (doesn’t eat or breath)
Host cell reproduces the virus

17. Structure…

18. Infection cycle… Lytic Cycle; Attachment of virus on cell membrane
Injection of DNA or RNA into cytoplasm
Cell replicates virus RNA or DNA
Assembly of viral structure (capsid & DNA)
Release; cell bursts and viruses escape

19. Lytic Cycle

20. Other ways… Lysogenic Cycle Virus attaches
Viral DNA is injected into cell
Viral DNA is incorporated into host DNA
Cell divides and daughter cells contain the viral DNA; process continues
May go into lytic cycle (scary)

21. Lysogenic cycle…

22. Retro-viruses Retrovirus is a virus that contains only RNA.
Virus has its own reverse transcriptase, an enzyme that makes DNA from RNA.
New DNA molecule is incorporated into the hosts DNA.
Example: HIV

23. HIV

24. HIV Anatomy

25. HIV Genes

26. HIV Gene Expression

27. HIV Infection Lytic cycle
Viral load usually large enough at 6 months after infection to test positive on ELISA or viral load tests
Contracted through blood transfusions, mothers milk, unprotected sexual contact, dirty needles…affects ALL ages, races, and genders!

28. Retrovirus…

29. HIV Therapies Docking Proteins (CD-4)
Reverse transcriptase (block action)
Proteases block building of Virus Proteins
Integrases block integration of vDNA into host DNA
AZT prematurely ends viral DNA replication
Natural Immunities (CD-4 altered or super immunity)
Other? (vaccine?)

30. Viruses: The Good, The Bad, The Ugly…
Viruses can be pathogens…
HIV, Influenza, Herpes, Chicken Pox…
Linked to cancer: Mono, Herpes, Hepatitis
Germ warfare: small pox
Viruses can be useful…
Can be used to inject useful genetic codes
Example; bacteria produce insulin
Vaccines; polio, measles, hepatitis…

31. Protists…

32. PROTISTA (protozoans)
Eukaryote (has nucleus and membrane bound organelles)
Single-celled
Two major categories
Protists
Blue-green algae

33. Are they plants? Animals?? Fungi???
Some protists are plant like!
Blue-green algae are photosynthetic and are the basis for aquatic food chains
Protists are animal like!
Carnivorous (ex. paramecium)
Parasitic (ex. Plasmodium)
Protists are like Fungi too!
Slime molds digest decaying logs and leaves

34. Protists: The good, the bad, the ugly…
Good: Form the basis of food chains
Ex. Algae
Bad: Can cause crop damage
Ex. Slime molds
Ugly: Cause serious disease
Ex. Malaria and Giardia

35. Giardia life cycle…

36. Giardia…

37. Malaria life cycle…

38. Malaria…

39. Fungi…

40. Fungi are biologically “weird”…
May be one simple cell or millions.
Have cell walls but are made of sugar.
Organelles can move from one cell to another
They can’t move nor can they make their own food.
They digest food outside themselves then absorb it through their cell walls.
Can reproduce sexually or asexually

41. Structure of Multicellular Fungi…
Cell Wall: Made of chitin, a complex polysaccharide (sugar).
Hyphae: Threadlike filaments that develop from fugal spores.
Mycelium: Network of hyphae.
Anchor fungi, invade host cell, and reproductive structures
Septa: divide hyphae into individual cells
Porous, cytoplasm and organelles can move freely.

42. Hyphae Mycelium

43. The Septa…

44. Reproduction…
Fragmentation: hyphae are severed and grow into new mycelium
Ex. Shoveling in a garden
Budding: Single celled fungi splits in two
Ex. Yeast
Spores: hyphae grow away from fungi and produce a case containing spores
Ex. Mushrooms

45. Classified by eating habits
Saprophytes: Feed off dead plants and animals.
Ex. Bread mold, mushrooms, bracket fungi.
Symbionts: Live with other organisms, mutual benefit.
Ex. Lichen (fungi outside, algae inside)
Parasites: Live off live organisms
Ex. Cause of Athletes Foot, Ringworm, etc.

46. Fungi; The good, the bad, the ugly…
Good: decompose organic material, make antibiotics (penicillin).
Bad: destroys food, wood products, shower curtains, etc…
Ugly: Pathogenic (yeast infection, athletes foot, ring worm, etc.)

47. Ring worm…

48. Athletes foot…

49. Questions???