1 / 49

KEY CONCEPT Bacteria and archaea are both single-celled prokaryotes.

Explore the world of prokaryotes - bacteria and archaea - their structures, functions, and roles in ecosystems and human health. Learn about their shapes, nutritional modes, and diverse characteristics.

johncarr
Download Presentation

KEY CONCEPT Bacteria and archaea are both single-celled prokaryotes.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. KEY CONCEPT Bacteria and archaea are both single-celled prokaryotes.

  2. Prokaryotes are widespread on Earth. • Prokaryotes can be grouped by their need for oxygen. • obligate anaerobesare poisoned byoxygen • obligate aerobes need oxygen • facultative aerobes can live with or without oxygen

  3. Modes of Nutrition • Saprobes– feed on dead organic matter • Parasites – feed on a host cell • Photoautotroph – use sunlight to make food • Chemoautotroph – oxidize inorganic matter such as iron or sulfur to make food

  4. Lactobacilli: rod-shaped Spirochaeta: spiral Enterococci: spherical Bacteria and archaea are structurally similar but have different molecular characteristics. • Bacteria commonly come in three forms. • rod-shaped, called bacilli • spiral, called spirilla or spirochetes • spherical, called cocci • Archaea have many shapes.

  5. What shape and grouping describes the bacteria pointed out below? A: Staphalacoccus B: Streptobacillus C: Diplococcus Clicker Question!

  6. Staphylococcus Bacterial

  7. Streptococcus Causes Strep Throat

  8. Bacillus - E. coli

  9. Streptobacilli

  10. Spirillum

  11. Leptospira

  12. Clicker Question! 1. _________ 2. _________ 3. _________ 4. _________ 5. _________ 6. _________ A. Staphylococcus B. Coccus C. Spirillum D. Bacillus E. Streptococcus F. Diplococcus

  13. Bacteria

  14. Archaebacteria

  15. Methanogens • Break down cellulose in a cow’s stomach • Produce marsh (methane) gas

  16. Extreme Halophiles • Live in very salty water • Use salt to generate ATP (energy) • Dead Sea, Great Salt Lake inhabitants

  17. Thermoacidophiles or Thermophiles • Live in extremely hot environments • Found in volcanic vents, hot springs, cracks on ocean floor that leak acid

  18. Clicker Question! Have a membrane bound nucleus and organelles: A: Prokaryotes B: Eukaryotes C: Nokaryotes

  19. BacteriavsArchaebacteria

  20. pili plasmamembrance flagellum chromosome cell wall plasmid This diagram shows the typical structure of a prokaryote. Archaea and bacteria look very similar, although they have important molecular differences. • plasmid • flagellum • pili • Bacteria and archaea have similar structures.

  21. GRAM NEGATIVE GRAM POSITIVE • The amount of peptidoglycan within the cell wall can differ between bacteria • Bacteria and archaea have molecular differences. • Archaea have different lipids entirely (cell walls lack peptidoglycan)

  22. Gram-negative bacteria have a thin layer of peptidoglycan and stain red. Gram-positive bacteria have a thicker peptidoglycan layer and stain purple. • stains polymer peptidoglycan • gram-positive stains purple, more peptidoglycan • gram-negative stains pink, less peptidoglycan • Gram staining identifies bacteria.

  23. conjugation bridge TEM; magnification 6000x Bacteria have various strategies for survival. • Prokaryotes exchange genes during conjugation. • Bacteria may survive by forming endospores.

  24. Pili in Conjugation Hairlike structures that help them attach to surfaces and allow for transfer of genetic material between two bacteria

  25. Sticky Bacterial Capsule Prevents drying out, allows it to attach to other surfaces, prevents it from being engulfed, & shelters it from antibiotics

  26. Flagella • Bacteria that are motile have appendages called flagella • A bacteria can have one or many flagella

  27. Monotrichous Lophotrichous Amphitrichous Peritrichous

  28. Clicker Question! What domain can be found in harsh environments like: Undersea volcanic vents, acidic hot springs, salty water? A: Bacteria B: Archaea C: Eukarea

  29. Clicker Question! Some bacteria gain energy from the sun (cyanobacteria), but the rest have to gain energy by consuming other organisms. These are called: A. Homotrophs B. Heteroeaters C. Heterotrophs D. Homoconsumers

  30. Clicker Question! What structure does this bacterium use for motility? A: Flagella B: Cilia C: Pili

  31. Clicker Question! Which type of bacteria is susceptible to antibiotics? A: Gram Positive (Dark Purple) B: Gram Negative (Light Pink)

  32. What kind of reproduction is depicted in the photo below? A: Asexual B: Conjugation C: Binary fission Clicker Question!

  33. KEY CONCEPTProkaryotes perform important functions for organisms and ecosystems.

  34. Prokaryotes provide nutrients to humans and other animals. • Prokaryotes live in digestive systems of animals. • make vitamins • break down food • fill niches

  35. yogurt, cheese • Bacteria help ferment many foods. • pickles, sauerkraut • soy sauce, vinegar

  36. Bacteria make Medicine • Vitamins • Antibiotics: • Streptomycin • Bacitracin • Tetracycline • Vancomycin

  37. Prokaryotes play important roles in ecosystems. • Prokaryotes have many functions in ecosystems. • photosynthesize • recycle carbon, nitrogen,hydrogen, sulfur • fix nitrogen

  38. Bioremediation uses prokaryotes to break down pollutants. • oil spills • biodegradable materials

  39. KEY CONCEPT Understanding bacteria is necessary to prevent and treat disease.

  40. Some bacteria cause disease. • Bacteria cause disease by invading tissues or making toxins. • A toxin is a poison released by an organism.

  41. may colonize new tissues • Normally harmless bacteria can become destructive.

  42. Normally harmless bacteria can become destructive. • immune system may be lowered

  43. Pathogens STD: Syphilis, gonorrhea, Chlamydia Respiratory: Strep throat, pneumonia, whooping cough, tuberculosis, anthrax Skin: Acne, boils Digestive: Gastroenteritis, food poisoning, cholera Nervous: Botulism, tetanus, bacterial meningitis Other: Lyme disease, typhoid fever

  44. Antibiotics are used to fight bacterial disease. • Antibiotics may stop bacterial cell wall formation. • Antibiotics do not work on viruses. • Prevention is best method to fight bacterial disease.

  45. A bacterium carries genes for antibiotic resistance on a plasmid. A copy of the plasmid is transferred through conjugation. Resistance is quickly spread through many bacteria. Bacteria can evolve resistance to antibiotics. • Bacteria are gaining resistance to antibiotics. • overuse • underuse • misuse • Antibiotics must be used properly.

More Related