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PROKARYOTES, BACTERIA, & VIRUSES

PROKARYOTES, BACTERIA, & VIRUSES. By carter reid. Eukaryotes v. Prokaryotes. Prokaryote Characteristics. Single cell No true nucleus F ew organelles Archaebacteria – extreme environments Eubacteria – “normal” bacteria. Eukaryotes v. Prokaryotes. Eukaryotes. Prokaryotes. Smaller

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PROKARYOTES, BACTERIA, & VIRUSES

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  1. PROKARYOTES, BACTERIA, & VIRUSES By carter reid

  2. Eukaryotes v. Prokaryotes

  3. Prokaryote Characteristics • Single cell • No true nucleus • Few organelles • Archaebacteria – extreme environments • Eubacteria – “normal” bacteria

  4. Eukaryotes v. Prokaryotes Eukaryotes Prokaryotes Smaller Not as complex No nucleus Have single strand of DNA and plasmid No membrane bound organelles Ex: Bacteria • Larger (up to 100 times!) • More complex • Nucleus • Have chromosomes • Membrane bound organelles • Ex: Animals, plants, protists

  5. CHARACTERISTICS of Bacteria • Prokaryotes – meaning “before a nucleus” • Divided into 2 domains • Bacteria • Archaea

  6. Archaebacteria • Dominate in extreme environments • 3 types • Thermoacidophiles • Hot, acidic areas (ex: sulfur hot springs, thermal vents on ocean floor) • Halophiles • Very salty areas, usually aerobic (ex: Great Salt Lake, Dead Sea) • Methanogens • No oxygen (anaerobic) areas, take in oxygen and give off methane (ex: sewegetreatment, swamps, bogs)

  7. EUBACTERIA • Most studied organism • Found everywhere, except extreme environments • Very strong cell walls (has peptidoglycan) • Some have a second cell wall

  8. PROKARYOTE STRUCTURE • Genetic material (DNA) • Flagella • Pili • Ribosomes • Capsule

  9. FUNCTION of the Structure • DNA – found in nucleoid (Remember: prokaryotes DO NOT have a nucleus) • Capsule – polysaccharide layer (aka sugar), prevents dry-out, helps attach cell to surfaces, prevents WBC’s from “eating” them • Pili – made of protein, hair-like, also helps attachment, can act as a bridge between cells • Flagella – helps with locomotion (aka movement) • Ribosomes – make proteins for the chromosomes

  10. HOW DO WE IDENTIFY BACTERIA?? • Shape • Cell Walls • Movement

  11. SHAPE of Bacteria • Cocci – spherical, round shape • Bacilli – rod-shaped • Spirilli – spiral - shaped • Strepto – long chains • Staphylo – clumps • Diplo - pairs

  12. Let’s Practice… DRAW THE FOLLOWING BACTERIA: • Staphylococcus • Streptococcus Now, write the types from the pictures below… 1. 2. 3.

  13. CELL WALLS • Have peptiodglycan (made of dissacharides & peptide fragments)  Why is it important for bacteria to have strong cell walls?

  14. MOVEMENT • Some are stationary • Some use flagella to move

  15. Bacteria REPRODUCTION • Sexual Reproduction – called Conjugation • Cells attach and exchange info • Asexual Reproduction – called Binary Fission • Chromosome replicates, then separates • Can happen every 20 min.  Becomes 1 BIL. IN 10 HRS!

  16. METABOLISM of Bacteria • Photoautotrophs • Do photosynthesis  need light to live • Called cyanobacteria • Release Oxygen into the environment • Chemoautotrophs • Do not require light • Break down & release inorganic compounds (Nitrogen or Sulfur) and keeps them cycling • Aerobes • Require oxygen to grow • Anaerobes • Do not require oxygen, use fermentation instead

  17. SURVIVAL • Endospores • Dormant cell • Resistant to harsh conditions • Forms around chromosome and small part of cytoplasm • Ex: anthrax, botulism, tetanus • Mutations • Quick reproduction, so genetic mutations help survival • Leads to “antibiotic - resistant bacteria”

  18. ECOLOGY of Bacteria • Bacteria are decomposersand return vital nutrients to the soil/environment • NORMAL FLORA – harmless bacteria in & out of your body • E.Coli in your intestines makes Vitamin K (for blood-clotting) • DIFFERENT from the food poisoning kind

  19. FOOD & MEDICINE • Cheese, yogurt, pickles – made w/the help of bacteria • Used to make CHOCOLATE (bacteria breaks down the cocoa bean covering) • MEDICINE – some anti-biotics (ex: tetracycline) originally made by bacteria

  20. DISEASE –CAUSING Bacteria • Only a small % of bacteria ACTUALLY cause disease • They harm in two ways… • Bacteria multiply quickly @ the infection site • Bacteria secrete a toxin that can cause harm (ex: Botulism – paralyzes nervous system cells)

  21. DISEASE –CAUSING Bacteria • PATHOGENS – disease-causing bacteria • ANTIBIOTICS – block the growth & reproduction of bacteria (they break down the cell wall)

  22. How to Control “BAD” Bacteria STERILIZATION – heat or chemically treat bacteria to kill it • Disinfect – chemical solution kills bacteria • Refrigerate – bacteria grows slower in the cold • Heat/Boil – high temps kill bacteria

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