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Bacteria

Bacteria. Insulin Production. Use an (restriction) enzyme from bacteria to cut out insulin gene. Insert the gene into a plasmid. The Bacteria will produce Insulin we can use! AND the bacteria will spread the plasmid via conjugation. Transformation.

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Bacteria

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  1. Bacteria

  2. Insulin Production • Use an (restriction) enzyme from bacteria to cut out insulin gene. • Insert the gene into a plasmid. • The Bacteria will produce Insulin we can use! • AND the bacteria will spread the plasmid via conjugation.

  3. Transformation • Bacteria can take up random DNA from the environment (like the plasmid with insulin) in a process called transformation. • It MIGHT give them a cool new gene to try out. • It MIGHT not.

  4. Transduction • A virus kills one bacteria and accidentally takes some of the host DNA with it. • When it infects the next bacteria & goes into the lysogenic cycle, it deposits the other bacteria’s genes.

  5. Prokaryotes • Lack Nucleus or MBO’s • Represent two Domains, Archae & Bacteria

  6. Differences Between Archae & Bacteria • 1. Cell wall composition (peptidoglycan) • 2. Environment (Archae = extremophiles) • 3. Nutrition (Archae= chemoauto • trophs) • Bacteria = all varieties

  7. Archae • Extremophiles • Halophiles = live in salty environments • Dead Sea & Great Salt Lake • Thermoacidophiles = Hot & Acidic • Deap Sea Vents & Hot Springs • Methanogens = obligate anaerobes • Swamps & Ruminid Stomaches  Produce Methane

  8. What are bacteria? • Bacteria are unicellular, living things • Prokaryotic cells; cells without a nucleus • Most do not make their own food, they obtain it by decomposing dead material (saprophytes) • Some manufacture their own food by undergoing photosynthesis (cyanobacteria)

  9. Identifying Prokaryotes • Cell Shape • Rod, sphere, or spiral • Colony growth • Cells arranged in particular ways • Form long chains • Grow in colonies of 2 cells together • Cell Wall • Chemical nature of cell wall is determined by staining. • Bacterial movement • Flagella • Some do not move • Some glide

  10. Shape one is rod shaped, also known as bacilli. Shape two is sphere shaped, also known as coccus. Shape three is spiral shape, also known as spirillum.

  11. Micrococcus luteus tetrads Bacillus cereus Vibrio Rhodospirillum

  12. How bacteria obtain energy • Autotrophs • Phototrophic autotrophs • (trap energy from sunlight) • Example: photosynthetic eubacteria • Chemotrophic autotrophs • Live in harsh environments; obtain energy from inorganic molecules like hydrogen sulfide, nitrites, sulfer and iron. • Example: Nitrosomonas (uses ammonia and oxygen to produce energy)

  13. How bacteria obtain energy • Heterotrophs • Bacteria that obtain energy by taking in organic molecules and then breaking them down and absorbing them. • Example: Salmonella grows on food such as raw meat

  14. Bacterial respiration • Energy is supplied by respiration and fermentation • Respiration involves oxygen and breaks down food molecules to release energy • Fermentation is energy production without oxygen • Obligate aerobes • Bacteria that require a constant supply of oxygen • Obligate anaerobe • Must live in the absence of oxygen • Example: Clostridium botulinum • If subjected to air and allowed to grow on food, it will produce toxins that cause severe food poisoning • Facultative anaerobes • Can survive with or without oxygen • Allow facultative anaerobes to live almost anywhere

  15. Bacterial growth and reproduction • Grow and reproduce at an incredible rate when conditions are favorable. Every 20min • Bacterial growth stays under control due to limiting factors such as nutrient availability and production of waste products. • Reproduction methods • Binary fission • Conjugation • Spore formation

  16. Binary fission • Asexual reproduction • When a bacterium is almost double in size, it replicates it’s DNA and divides in half. • Example: E. coli

  17. Conjugation • A sex pilli bridge of protein forms in between 2 bacterial cells connecting them. • A plasmid (ring of up to 12 genes) is exchanged • Recipient cell ends up with different combo of genes.

  18. Spore formation • Spores form when conditions become unfavorable. • Endospore is a type of spore that forms a thick internal wall that protects the DNA and cytoplasm. • Endospores can remain dormant for months to years while waiting for favorable conditions to arise.

  19. Why are bacteria important? • Food production • Yogurt, cheese, buttermilk, sour cream • Used in industry • Digest petroleum; clean up oil spills • Used in mining • Symbiosis • Digestion for example • Help cattle digest cellulose

  20. Bacteria and the environment • Nutrient flow • Nitrogen cycle • Nitrogen-fixing bacteria • Denitrification • Saprophytes • Use complex molecules of a once-living organism for nutrients • Sewage decomposition • Bacteria added to sewage to treat waste water

  21. Downside of bacteria • Pathogens • Disease causing agents • Small number of bacteria are pathogens • Examples of pathogenic bacterial infections: • Syphilis, cholera, tuberculosis, bubonic plague • Pathogens cause disease by: • Damaging cells and tissues for use of nutrients • Release toxins

  22. Treating bacterial infections • Antibiotics attack and destroy bacteria by preventing the cross polymerization of peptidoglycan

  23. Gram Staining • By treating bacteria with dye you can differentiate between Gram positive (purple) or negative (pink) • Gram positive have more peptidoglycan *& negative have less….. • Which one would you rather be infected by?

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