ISP 26.1

2. ISP 26.1

3. How Bacteria Are Classified • Eubacteria or Archaea (Which Domain?) • Mode of Nutrition • Ability to produce Endospores • Means of Mobility (Flagella?) • Shape (cocci, bacilli, or spirilla) • Gram Stain • Positive – thick peptidoglycan cell wall • Negative – thin peptidoglycan cell wall

4. Prokaryotic Nutrition • Bacteria differ in their need for, and tolerance of, oxygen (O2). • Obligate anaerobesare unable to grow in the presence of O2; ex. botulism, gas gangrene, and tetanus • Facultative anaerobesare able to grow in either the presence or absence of gaseous O2. • Aerobic organisms (Obligate aerobes) - including animals and most prokaryotes) require a constant supply of O2 to carry out cellular respiration.

5. How Bacteria Obtain Energy • Every type of nutrition, except for ingestion of whole food, is found in bacteria. • Autotrophs – manufacture their own organic compounds • Photoautotrophs • Chemoautotrophs • Heterotrophs – must obtain their energy by consuming organic substances produced by autotrophs. • Parasites • Saprophytes (Saprobes) • Decomposers

9. Pasteur’s experiments disproved the long held belief in spontaneous generation

10. Reproduction in Prokaryotes

11. Sources of Genetic Variation • In bacteria, genetic recombination can occur in three ways. • Conjugation - occurs when a bacterium passes DNA to a second bacterium through a tube (sex pilus) that temporarily joins two cells; occurs only between bacteria in same or closely related species. • Transformation - involves bacteria taking up free pieces of DNA secreted by live bacteria or released by dead bacteria. • Transduction -bacteriophage transfer portions of bacterial DNA from one cell to another.

12. Bacterial Conjugation Bacterial Conjugation Link

13. Transformation in Bacteria Transformation in Bacteria Link

14. General Transduction General Transduction Link

15. Endospore Formation • Some bacteria form resistant endospores in response to unfavorable environmental conditions. • Endospores survive in the harshest of environments: desert heat and dehydration, boiling temperatures, polar ice, and extreme ultraviolet radiation.

16. Heterotrophic Prokaryotes • Some heterotrophs are symbiotic, forming intimate, long-term relationships with members of other species; includes: • Mutualistic • Commensalistic • parasitic relationships

17. The bacteria of genus Rhizobium invade the roots of legumes – resulting in the formation of nodule – The bacteria convert atmospheric nitrogen to an organic nitrogen that the plant can use

18. Heterotrophic Prokaryotes • Commensalistic bacteria live in or on organisms of other species and cause them no harm. • Parasitic bacteria are responsible for a wide variety of infectious plant, animal and human diseases.

19. The Bacteria Gram Stain & Shape • The Gram stain procedure (developed by Hans Christian Gram) differentiates bacteria. • Gram-positive bacteria stain purple, whereas Gram-negative bacteria stain pink. • This difference is dependent on the thick or thin (respectively) peptidoglycan cell wall.

20. The Bacteria • Bacteria and archaea have three basic shapes. • spirillum- spiral-shaped. • bacillus - elongated or rod-shaped bacteria • Coccus - bacteria are spherical • Cocci and bacilli tend to form clusters and chains of a length typical of the particular species.

22. The Archaea • Carl Woese - base sequence of their rRNA differs from Bacteria • Other differences: • Archaea do not have peptidoglycan in their cell walls like the Bacteria • Archaea biochemical more like Eukarya than Bacteria • Archaea now thought to be more closely related to Eukarya than to Bacteria

24. The Archaea • Types of Archaea • Methanogens live under anaerobic environments (e.g., marshes) where they produce methane. • Halophiles require high salt concentrations (e.g., Great Salt Lake). • Thermoacidophiles live under hot, acidic environments (e.g., geysers).

25. Kingdom Protista • Catch all Kingdom - artificial & used more for convience. • Eukaryotic cells (Endosymbiotic Theory) • Most are unicellular (some filamentous, colonial or multicellular) • Animal-like, plant-like or fungus-like • Asexual reproduction the norm, but some reproduce sexually.

26. Endosymbiotic theory

27. Kingdom Protista • Complexity • Eukaryotic • Autotrophic or Heterotrophic • Highly varied life cycles (asexual & sexual reproduction) • Highly specified organelles • Symbiotic relationships (parasitismmutualism)

29. The Green Algae • Green algae are believed to be closely related to the first plants because both of these groups • have a cell wall that contains cellulose, • possess chlorophylls a& b • store reserve food as starch inside of the chloroplast.

30. Red Algae

31. Brown Algae

32. Diatoms & Golden Brown Algae CO 22

33. Dinoflagellates

34. Red Tide

35. Euglenoids

37. Zooflagellates

38. Ameboids

39. Ciliates

40. Sporozoans(Malaria)

41. Slime Molds

42. Slime Molds

43. Water Molds Figure 22.19

44. Kingdom Fungi • Multicellular Eukaryotes • Heterotrophic by absorption • Saprotrophic decomposers -breaking down wastes or remains of plants & animals • Parasitic, mutualistic • Others form an association with a green alga or cyanobacterium to form a lichen • Energy reserve Glycogen (unlike plants)

46. Terms to know: Hyphae (singular hypha) Mycelium (singular mycelia) Chitin

47. Figure 23.3

48. Pg 410