1 / 24

Bacteria

This chapter discusses the structure and reproduction of bacteria, including their different shapes, cell walls, and DNA. It also explains how bacteria can cause diseases, the importance of bacteria in various ecosystems, and methods for preventing and treating bacterial infections.

sphelps
Download Presentation

Bacteria

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. Bacteria Chapter 23

  2. Standards • Standard 1: Cells • CLE 3216.1.6 • Describe the relationship between bacteria, protists, and viruses and their host cells • Prokaryotes

  3. Bacteria • Prokaryote (no nucleus) • Small • 2 groups: • Archaebacteria • Eubacteria

  4. Eubacteria • Abundant • Cell walls contain peptidoglycan (carb) • 2 cell walls (some) • Exs: E.coli, Streptococci, TB, meningitis

  5. Eubacteria Structure

  6. Archaebacteria • Lack peptidoglycan • DNA closer to eukaryote • Harsh environments (thick mud, digestive system of animals, great Salt Lake)

  7. Archaebacteria Structure

  8. Shape • Bacilli - rod shaped • Cocci - sphere shaped • Spirilla - spiral or corkscrew shaped

  9. Cell Wall • Gram positive - detects peptidoglycan (purple) • Gram negative - no peptidoglycan (red or pink)

  10. DNA • A single closed loop of double-stranded DNA attached to one point to cell membrane • Not enclosed in a nucleus • Some have Plasmids - Carry genes that cause disase - Carry genes that provide resistance to atibiotics

  11. Capsules and Pili • Capsule – outer covering that protects the cell from drying out or harsh chemicals • - allows cell to connect to host cells and tissue • Pili – help bacteria to connect to each other and to other surfaces

  12. Endospores • A thick-coated resistant structure • Helps bacteria to survive in harsh conditions for long times • Resistant to high temps, strong chemicals, radiation, drying out, and environmental extremes

  13. Movement • Flagella: • Allows bacteria to move forward, backward, and to rotate and flip

  14. Heterotrophs (eat others) • Chemoheterotroph- needs to eat other organisms • Photoheterotroph - photosynthetic but also need to eat organisms to get carbon

  15. Habitats • Bacteria live in certain places and habitats based on their biochemical abilities • Bacteria live in different places based on certain conditions • Ex: oxygen or not temperature of environment pH of environment

  16. Autotrophs (make own food) • Photoautotroph – use sun to get energy • Chemoautotroph - use ammonia, sulfur, iron, etc. to get energy

  17. Reproduction • Divide quickly if food and space available • Binary fission • Conjugation • Spore Formation

  18. Binary Fission • When bacterium replicates DNA & divides in half producing 2 identical daughter cells • Asexual

  19. Conjugation • When 2 bacteria exchange genetic material • Creates diversity • Not sexual (no new cells made)

  20. Spore Formation • When growth conditions are harsh • Endospore - internal wall in bacteria that surrounds DNA • Ex: Anthrax

  21. Bacterial Importance • Decomposers • Nitrogen fixers • Human uses - making food & beverages, remove waste from water, synthesize drugs

  22. Bacterial Disease • Any disease causing bacteria = pathogen • Bacteria eats cells for food in host • Ex: TB • Bacteria release toxins interfering with normal functions (exo and endotoxins) • Ex: strep throat - toxins in blood stream

  23. Disease Prevention • Vaccine - weakened or killed pathogen - causes body to produce immunity • Antibiotics - block the growth and reproduction of bacteria (penicillin) • Sterilization - high temps kill bacteria • Disinfectant - chemical soln that kills bacteria • Food Storage & Processing - cool temps decrease reproduction - boiling, frying, steaming sterilizes

  24. Common Bacterial Diseases • Lyme Disease • Tetanus • TB • Meningitis • Strep Throat • Ear Infection

More Related