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

3. 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

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

5. 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

6. AP Biology Prokaryotic Cell Wall Structure  Positive  Simple, lots of peptidoglycan, violet  Negative  Complex, little peptidoglycan, pink/red  More THREATENING/resis tant to antibiotics

7. AP Biology Prokaryote Structure  Pili  Appendages  Capsule  Protective layer, helps with adhesion  DNA  One, circular, loop  no membrane-bound organelles  Plasmid  Rings of DNA with a few genes prokaryote cell eukaryote cell

8. AP Biology Plasmids  F plasmid  Male!  Hfr  Cell with plasmid built into chromosome  R plasmid  Resist antibiotics

9. 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

10. AP Biology Taxis  Movement away/toward a stimulus  Chemotaxis  Respond to chemical (oxygen, food)  Phototaxis  Respond to light  Geotaxis  Respond to gravity

11. AP Biology Genetic variation in bacteria  Mutations  bacteria can reproduce every 20 minutes  binary fission  error rate in copying DNA  1 in every 200 bacteria has a mutation  Genetic recombination  bacteria swap genes  plasmids  small supplemental circles of DNA

12. AP Biology Reproduction  Binary Fission  Asexual  Transformation  Takes up foreign, naked, genes from environment  Conjugation  Direct transfer of genes through pili  Transduction  Virus transfers genes between prokaryotes

13. 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

14. 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  needed for synthesis of proteins & nucleic acids  plant root nodules  help in digestion (E. coli)  digest cellulose for herbivores  cellulase enzyme  produce vitamins K & B 12 for humans  produce foods & medicines  from yogurt to insulin