AP Biology Prokaryotes Domain Bacteria Domain Archaea Domain Eukarya Common ancestor

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

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

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

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

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

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

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

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

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

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

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

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