Bacteria

1. Bacteria Structure and Function

2. Prokaryote & Eukaryote Evolution

3. Cellular Evolution • Current evidence indicates that eukaryotes evolved from prokaryotes between 1 and 1.5 billion years ago • Two theories: 1. Infolding theory 2. Endosymbiotic theory

4. Infolding Theory • The infolding of the prokaryotic plasma membrane gave rise to eukaryotic organelles. infolding organelle

5. Endosymbiotic Theory • Endosymbiosis refers to one species living within another(the host) • Movement of smaller photosynthetic & heterotrophicprokaryotes into larger prokaryotic host cells • Formed cell organelles chloroplast mitochondria

6. Prokaryotic & Eukaryotic Cells

7. Earliest Prokaryotes • Most numerousorganisms on Earth • Include allbacteria • Earliest fossils date2.5 billion years old

8. Classification of Life

9. Three Domains of Life • Archaea – prokaryotes living in extreme habitats • Bacteria- Cyanobacteria and eubacteria • Eukarya – Protozoans, fungi, plants, & animals

10. Kingdoms of Bacteria Archaebacteria: • Found in harsh environments • Undersea volcanic vents, acidic hot springs, salty water

11. Archaebacteria

12. Kingdoms of Bacteria Eubacteria: • Called the true bacteria • Most bacteria are in this group • Include photosynthetic Cyanobacteria

13. Eubacteria

14. Characteristics of Bacteria

15. Bacterial Structure • Microscopic prokaryotes • No nucleus or membrane-bound organelles • Contain ribosomes • Single, circular chromosome in nucleoid region

16. Bacterial Cell

17. Protection • Cell Wall made of Peptidoglycan • May have a sticky coating called the Capsule for attachment to host or other bacteria

18. Sticky Bacterial Capsule

19. Bacterial Structure • Have small rings of DNA called Plasmids • Unicellular • Small in size (0.5 to 2μm) PLASMIDS

21. Bacterial Structure • Infoldings of cell membrane carry on photosynthesis & cellular respiration • Infoldings called Mesosomes

22. Mesosomes MESOSOME

23. Bacterial Structure • Most grow best at pH of 6.5 to 7.0 • Many act as decomposers recycling nutrients • Some cause disease

24. Bell Ringer • Bacteria have small rings of DNA called _________. • The bacterial cell wall is made up of ______________. • Which kingdom of bacteria is called “true bacteria”

25. Staphylococcus Bacterial

26. Useful Bacteria • Some bacteria can degrade oil • Used to clean up oil spills

27. Useful Bacteria • Other uses for bacteria include making yogurt, cheese, and buttermilk.

28. Flagella • Bacteria that are motile have appendages called flagella • Attached by Basal Body • A bacteria can have one or many flagella

30. Flagella • Made of Flagellin • Used for Classification • Monotrichous: 1 flagella • Lophotrichous: tuft at one end • Amphitrichous: tuft at both ends • Peritrichous: all around bacteria

31. Monotrichous Lophotrichous Amphitrichous Peritrichous

32. Question: What is this type of bacteria ?

33. Pili • Short protein appendages • Smaller than flagella • Adhere bacteria to surfaces • Used in conjugation for Exchange of genetic information • Aid Flotation by increasing buoyancy

34. Pili in Conjugation

35. Bacterial Shapes

36. Shapes Are Used to Classify • Bacillus: Rod shaped • Coccus: Spherical (round) • Vibrio: Comma shaped with flagella • Spirillum: Spiral shape • Spirochete: wormlike spiral shape

38. Grouping of Bacteria • Diplo- Groups of two • Strepto- chains • Staphylo- Grapelike clusters

41. Diplococcus

42. Streptococcus Causes Strep Throat

43. Staphylococcus

44. Bacillus - E. coli

45. Streptobacilli

46. Spirillum

47. Spirochetes

48. Leptospira

50. Bacterial Kingdoms