Prokaryotes and the nonliving Archaea & Bacteria Domains with Viruses C2, pp24-46.

Prokaryotic facts Most numerous organisms on Earth Earth’s earliest fossils (Bacteria 3.5 x 109 yrs old; Archaean - 2.7 x 109 yrs ago). Lack membrane-bound organelles rRNA analysis shows Archaea linked more to Eukaryotes than to Bacteria Generally have cell wall, cell membrane, cytoplasm with ribosomes, DNA, & small ions/ molecules

Archaea vs. Bacteria Cell walls DNA Sporulation Groups Bacteria have peptidoglycans. Archaea don’t. DNA Archaea have introns. Bacteria don’t. Sporulation Some bacteria do. Archaeans don’t. Groups A: Methanogens, halophiles, thermoacidophile B: Bacilli, cocci, spirilla; gram-pos & gram-negative

Bacterial Cell Characteristics Capsule: protects & aids in attachments Cell wall: protects & gives shape Cell membrane: control passage in/out of cells Plasmid: carries genes in small DNA loop Endospore: contains DNA; thick-coated Pilus: attachment during conjugation Flagellum: propels cells Gram-neg outer membrane: deflect antibiotics

Bacteria Nutrition Autotroph Heterotroph Photoautotroph (uses sunlight; gets C from CO2) Chemoautotroph (gets Energy from inorganic compound; gets Carbon from CO2) Heterotroph Photoheterotroph (uses Light Energy but get Carbon from other organisms) Chemoheterotroph (gets energy & C from other organisms)

Prokaryotic Reproduction Single circular loop of DNA is copied Binary fission yields 2 identical daughter cells Exchanging DNA Lateral gene transfer Between different species; natural conditions Transformation Gets DNA from its outside environment Conjugation Gets DNA from other prokaryote via sex pilus Transduction Virus copies piece of host DNA & transfers it to others

Prokaryotic Habitats Obligate anaerobes = no O2 allowed Facultative anaerobes = + O2 is OK Obligate aerobes = O2 necessary Psychrophilic = cold-loving (0oC – 20oC) Mesophiles = average (20o-40oC) Thermophiles = hot-loving (45o- 110oC) Acidophiles = pH at or below 6.0 Most prefer neutral pH range of 6.5 – 7.5

Bacterial disease Disease Bacterium Anthrax Botulism Tetanus Cholera Gonorrhea Dental caries Food poisoning Lyme disease Bacterium Bacillus anthracis Clostridium botulinum Clostridium tetani Vibrio cholerae Neisseria gonorrhoeae Streptococcus mutans Salmnella typhimurium Borrelia burgdorferi

Bacteria in Industry Foods Medicine Agriculture Fermentation  buttermilk, sour cream, yogurt Cheeses, sauerkraut, pickles, kimchi, coffee, soy Medicine Acetone, acetic acid, enzymes, antibiotics, insulin Agriculture Endotoxins as insecticides Bioremediation = degrade petroleum

Viruses Nonliving Shapes Noncellular DNA or RNA inside a protein coat + oily envelope No organelles for homeostasis, metabolism, or reproduction May use RNA instead of DNA for heredity Shapes Helical Icosahedral Complex

Viral Classification By type of nucleic acid possessed RNA or DNA Shape & structure Viral strains/ serotypes Organism they infect (host) Avian influenza Can jump to new species, however Place identified Ebola from Ebola Valley, Congo region, Africa

Viral Diseases Rhinovirus Influenza virus HIV-1 Common cold Evolve extremely quickly RNA virus hijack’s host machinery Survive on moist surface ~ 2 wks HIV-1 Retrovirus (injected RNA  D  host DNA) Can lie dormant for years

Virus Life Cycle Attach to host plasma membrane Be engulfed into host cell Viral coat shed Enters host nuclei for replication Produces viral proteins on host’s ribosomes Nucleic acid is housed in protein New viruses exit cell via budding or cell lysis

Treating Viral Diseases Antibiotics don’t work Immune system fights back with eosinophils & T-helper cells with fever But usually overwhelmed eventually Drug cocktails Disable viral reproduction Can have serious side effects