2. AP Biology Archaebacteria & Bacteria Classification  Old 5 Kingdom system  Monera, Protists, Plants, Fungi, Animals  New 3 Domain system  reflects a greater understanding of evolution & molecular evidence  Prokaryote: Bacteria  Prokaryote: Archaebacteria  Eukaryotes  Protists  Plants  Fungi  Animals Prokaryote Eukaryote

3. AP Biology Kingdom Protist Kingdom Fungi Kingdom Plant Kingdom Animal Kingdom Archaebacteria Kingdom Bacteria

4. AP Biology 2007-2008 Prokaryotes Domain Bacteria Domain Archaebacteria Domain Bacteria Domain Archaea Domain Eukarya Common ancestor

5. AP Biology Bacteria live EVERYWHERE!  Bacteria live in all ecosystems  on plants & animals  in plants & animals  in the soil  in depths of the oceans  in extreme cold  in extreme hot  in extreme salt  on the living  on the dead Microbes always find a way to make a living!

6. AP Biology Bacterial diversity rods and spheres and spirals… Oh My!

7. AP Biology Prokaryote Structure  Unicellular  bacilli, cocci, spirilli  Size  1/10 size of eukaryote cell  1 micron (1um)  Internal structure  no internal compartments  no membrane-bound organelles  only ribosomes  circular chromosome, naked DNA  not wrapped around proteins prokaryote cell eukaryote cell

8. AP Biology Prokaryote vs. Eukaryote Chromosome double helix Prokaryote Eukaryote

9. AP Biology  The typical prokaryotic genome  Is a ring of DNA that is not surrounded by a membrane and that is located in a nucleoid region  Some species of bacteria  Also have smaller rings of DNA called plasmids 1  m Chromosome

10. AP Biology  Many prokaryotes form endospores  Which can remain viable in harsh conditions for centuries Endospore 0.3  m Figure 27.9

11. AP Biology Variations in Cell Interior internal membranes for photosynthesis like a chloroplast (thylakoids) internal membranes for respiration like a mitochondrion (cristae) aerobic bacterium mitochondria cyanobacterium (photosythetic) bacterium chloroplast

12. AP Biology Prokaryote Cell Wall Structure peptide side chains cell wall peptidoglycan plasma membrane protein Gram-positive bacteria Gram-negative bacteria peptidoglycan plasma membrane outer membrane outer membrane of lipopolysaccharides cell wall peptidoglycan = polysaccharides + amino acid chains lipopolysaccharides = lipids + polysaccharides

13. AP Biology  The cell wall of many prokaryotes  Is covered by a capsule, a sticky layer of polysaccharide or protein 200 nm Capsule Figure 27.4

14. AP Biology Motility  Most motile bacteria propel themselves by flagella  Which are structurally and functionally different from eukaryotic flagella  Many exhibit taxis, the ability to move towards or away from certain stimuli Flagellum Filament Hook Cell wall Plasma membrane Basal apparatus 50 nm Figure 27.6

15. AP Biology Prokaryotic metabolism  How do bacteria acquire their energy & nutrients?  photoautotrophs  photosynthetic bacteria  chemoautotrophs  oxidize inorganic compounds  nitrogen, sulfur, hydrogen…  heterotrophs  live on plant & animal matter  decomposers & pathogens

16. AP Biology  Obligate aerobes  Require oxygen  Mycobacterium tuberculosis  Facultative anaerobes  Can survive with or without oxygen  Bacillus anthracis  Obligate anaerobes  Are poisoned by oxygen  Clostridium botulinum

17. AP Biology  Cooperation between prokaryotes  Allows them to use environmental resources they could not use as individual cells  In the cyanobacterium Anabaena  Photosynthetic cells and nitrogen-fixing cells exchange metabolic products Photosynthetic cells Heterocyst 20  m

18. AP Biology Archaea  Archaea share certaintraits with bacteria  And other traits with eukaryotes Table 27.2

19. AP Biology  Extreme thermophiles  Very hot environments  Methanogens  Swap and marshes  Produce methane as a waste product  Extreme Halophiles  High saline environments Figure 27.14 Some Archea live in extreme environments

20. AP Biology Bacteria as pathogens  Disease-causing microbes  plant diseases  wilts, fruit rot, blights  animal diseases  tooth decay, ulcers  anthrax, botulism  plague, leprosy, “flesh-eating” disease  STDs: gonorrhea, chlamydia  typhoid, cholera  TB, pneumonia  lyme disease

21. AP Biology Bacteria as beneficial (& necessary)  Life on Earth is dependent on bacteria  decomposers  recycling of nutrients from dead to living  nitrogen fixation  only organisms that can fix N from atmosphere to ammonia  Bioremediation  Remove pollutants from the environment  help in digestion (E. coli): Symbiosis  digest cellulose for herbivores  cellulase enzyme  produce vitamins K & B 12 for humans  produce foods & medicines  from yogurt to insulin