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Prokaryotes

Prokaryotes. By Aram Gebretensae and Quddus Akinlusi. Some facts and basics. Prokaryotes… Have a biomass 10x of eukaryotes Are widespread due to quick adaption Multi diverse group Classified as two domains, Achaea and Bacteria (differ in structural, physical, and biochemical character).

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Prokaryotes

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  1. Prokaryotes By Aram Gebretensae and QuddusAkinlusi

  2. Some facts and basics Prokaryotes… • Have a biomass 10x of eukaryotes • Are widespread due to quick adaption • Multi diverse group • Classified as two domains, Achaea and Bacteria (differ in structural, physical, and biochemical character)

  3. What’s the difference?!

  4. Function, Structure, and genetic adaptive style • Most are unicellular • Cells range from 1-5micrometer smaller than eukaryotic cells • Most common shapes, rods(bacilli), spheres (cocci), spiral.

  5. Cell-surface structure, why is it important • Determines how potent the prokaryote is • Gives guidelines as to how scientist should develop an antibiotic if such prokaryote is said to the harmful

  6. Da Cell Wall • Main component • Maintains shape and prevent lyse • Under salty conditions bacteria can’t grow (food preservation) • Made of peptidoglycan, a network of modified-sugar polymers cross linked by short peptides.

  7. Gram Staining • Develop by Danish physician Hans Christian Gram • Used for virus identification. • Gram positive have more peptidoglycan • Gram negative have less peptidoglycan and is more complex • Gram negs are more dangerous

  8. world application • Needed to check potency of bacteria • Anti-peptidoglycan drugs are made to treat the disease • EX. Penicillin

  9. Cell defense and movement • Cell all covered by capsule or fimbriae - serves as a key so bacteria could bind to cells. - shields bacteria from immune system attacks Cell moves through series of chains flagellins called a flagellum

  10. Motility • Definition: ability to spontaneously and actively move • Almost all prokaryotes are capable of this • In a heterozygous environment , they exhibit taxis, movement towards or away from a stimulus • Most common is chemo taxis (chemo-chemical, taxis-order

  11. Internal and genomic organization • Much simpler genome • Has about 1/1000 of eukaryote DNA with little protein appearance • Most chromosome is in the nucleoid • Also has plasmid that has few genes • Plasmids are useful in protection against antibiotics

  12. Reproduction and Adaptation • Division is through binary fission • Some reproduce in 1-3 hrs, while some create new in 20 min • Prokaryote presence is limited b/c of nutrition competition and digestion by other organisms. • Some can develop resistant cells called endospore; for example the anthrax bacteria • Adapt quickly through fast reproduction that causes increase likelihood of beneficial mutations

  13. Nutritional and metabolic adaptations that evolved • Four models of nutrition are Photoautotroph: organism that obtain energy from light Chemoautotroph: organism that obtain energy from chemical Photoheterotroph: use light for energy but must obtain carbon organically Chemoheterotroph: must consume both organic molecules for both light and carbon

  14. Photoautotroph and heterotroph organism that obtain energy from light

  15. Nitrosomonas bacteria (Chemoautotroph ) Use energy from simply oxidation of simple inorganic compounds to make food

  16. Anthrax(Chemoheterotrophic) Anthrax is a gram-positive aerobic rod chemoheterotroph who is immune to phagocytosis.

  17. Metabolic relationship to oxygen • Metabolic depends on oxygen • Obligate aerobes use 02 for cellular respiration • Facultative anaerobes use 02 but can also grow on fermentation • Obligate anaerobes are poisoned by 02 so some stick to fermentation or get chemical energy through anaerobic respiration

  18. Metabolic co-op • Co-op between prokaryotes allows them to use environmental resources they couldn’t use as individual • Ex, cynacobactrium anabaena has genes for both nitrogen fixation and photosynthesis but can’t do both. • Filamentary cell carry out photosynthesis while heterocytes do nitrogen fixation

  19. Metabolic relationship to oxygen • Metabolic depends on oxygen • Obligate aerobes use 02 for cellular respiration • Facultative anaerobes use 02 but can also grow on fermentation • Obligate anaerobes are poisoned by 02 so some stick to fermentation or get chemical energy through anaerobic respiration

  20. Molecular systemiacs • In 1970, carl Woese and his colleagues, through prokaryotes gene sequence, found that prokaryotes, once labeled bacteria, were actually more related to eukaryotes. • Were later placed as Archea • This changed the Phylogenic prokaryote chart

  21. Archaea • Share similarities between eukaryotes and bacteria • 1st Prokaryotic Achaea were extremophiles, (lovers of extreme conditions) • Extremophile include thermophile, halophile • Methanogens use co2 to oxidize H2 to create Methane • All extremophiles and Methanogens are members of the clade Euryarcheota

  22. Chemical Recycling • Prokaryotes like Chemoheterotrophic ones function as decomposers • Other prokaryotes like cyanobacteria convert inorganic products into forms that can be consumed by other organisms

  23. Symbiotic relationships • Ecological relationship between organism is called symbiosis • Symbiont is smaller, larger is the host • 3 symbiotic relationship are commensalism, mutualism, parasitism • Commensalism one benefit, mutualism both, parasitism, one benefit at the expanse of the other • The well being of many eukaryotes depend on the mutualism of prokaryotes in the body

  24. Pathogenic prokatytes • Cause about ½ of human diseases • Ex. Lyme disease is caused by the transmittance spirochete Borrelia burgdorferi through ticks in deer and field mice • Classified as exotoxins and endotoxins • Exotins are proteins secreted by these prokaryotes • Endotoxins are lippolysaccrides components that are released when the prokaryote dies

  25. Sources • http://www.tutorvista.com/content/biology/biology-i/cell-structure/prokaryotic-eukaryotic-cells.php • http://www.schmidtandclark.com/bacillus-cereus • Campbell, N. A., & Reece, J. B. (2004). Mendel and the gene idea. Benjamin Cummings. Retrieved from http://wps.aw.com/bc_campbell_biology_7/ • Moore. (n.d.). Mountain empire community college. Retrieved from http://water.me.vccs.edu/courses/env108/lesson5b.htm • Bailey, R. (n.d.). About.com. Retrieved from http://biology.about.com/od/cellanatomy/ss/prokaryotes.htm • Ganesh , K. (2010). Modes of nutrition in different types of plants. Retrieved from http://www.tutorvista.com/content/biology/biology-iv/plant-nutrition/plant-nutrition-modes.php • Symbiotic relationships. (2011, August 26). Retrieved from http://www.buzzle.com/articles/symbiotic-relationships-examples.html • geology.com. (2011). Retrieved from http://geology.com/articles/ticks-lyme-disease/

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