Prokaryotes & Viruses

Taxonomy Domain Eukarya KingdomAnimalia PhylumChordata ClassMammalia OrderCetacea FamilyDelphinidae GenusTursiops Speciestruncatus Bottlenose dolphin

Domains Eubacteria (Bacteria) Archaebacteria (Archaea) Eukarya Kingdom Protista Kingdom Fungi Kingdom Plantae Kingdom Animalia

Prokaryotes vs. Eukaryotes Prokaryotes—simplest, most “primitive” bacteria Eukaryotes— “true” cells, more “advanced” Complex organisms, multicelled

Prokaryotes No membrane around nucleus No true organelles Single chromosome (nucleoid) May have plasmids Cell wall (most) Reproduce by prokaryotic fission

Bacterial Shapes Coccus (cocci)—spherical Bacillus (bacilli)—rod Sprillum (spirilla)—spiral, twist

Bacterial Structures Cell wall Peptidoglycan (polysaccharide) Maintain shape ID species Gram-positive—thick wall Stain purple Gram-negative—thin wall Stain pink

Bacterial Structures Glycocalyx—capsule or slime layer Attach to structures (teeth, intestine, rocks, etc.) Protection Pili—thin, hair-like proteins Adhere to surfaces Adhere to other baceria Flagellum Movement

Metabolism Photoautotroph Energy from sun (photosynthesis) Carbon from CO 2 Chemoautotroph Energy from simple compounds (iron, sulfur, etc.) Carbon from CO 2 Photoheterotroph Energy from sun Carbon from organic compounds Chemoheterotroph (most common kind) Energy from simple compounds Carbon from organic compounds

Prokaryotic Fission Similar to mitosis, but simpler DNA duplicates DNA molecules move to opposite sides of cell New cell membrane & wall form across middle Cell divides

Conjugation Transfer section of DNA from one cell to another Transfers genes, characteristics Antibiotic resistance

Domain Eubacteria Cyanobacteria One of most primitive kind Photoautotrophs Produce oxygen “Fix” nitrogen (convert N 2 gas to nitrogen compounds)

Domain Eubacteria Proteobacteria All gram-negative Chemoautotrophs Important to nutrient cycles Rhizobium Roots of legumes (peas, soybeans, etc.)

Domain Eubacteria Chlamydia Intracellular parasites One species causes STD Spirochaetes Free-living, parasites, or symbionts Motile “springs” Borrelia burgdorferi—Lyme disease

Domain Eubacteria Gram-positives Still being sorted out Chemoheterotrophs (most) Lactobacillus—dairy foods (i.e. yogurt) Bacillus anthracis—anthrax Clostridium tetani—tetanus

Domain Archaebacteria “Extremophiles” Primitive, but resemble other bacteria Different cells walls (no peptidoglycan)

Domain Archaebacteria Thermophiles Heat lovers Sulfur used to make ATP Temperatures can exceed 110 o C

Domain Archaebacteria Methanogens Create methane gas Marshes, Antarctica, deep ocean Symbionts (termites, cattle) Important to carbon cycling Anaerobes

Domain Archaebacteria Halophiles Salt lovers Environments 10x salinity of sea water Dead Sea, Great Salt Lake

Living things must…. Acquire energy Metabolize Maintain homeostasis Grow Reproduce Respond Adapt

Viruses Noncellular Infectious parasite Two main characteristics Protein coat around nucleic acid (DNA or RNA) Cannot reproduce itself

Viruses Herpes Smallpox Hepatitis B Rhino virus (common cold) HIV Influenza Rabies

Viral Multiplication Attachment Penetration Replication & synthesis Assembly Release

Viral Multiplication Lytic Pathway—host cell bursts (lysis) & dies, releasing viruses Very rapid

Viral Multiplication Lysogenic Pathway—host cell lives, viral DNA merges w/ host’s & is duplicated w/ host DNA

Latent Period virus in lysogenic pathway, reproducing but not showing disease Stress or other stimulus signals virus into lytic pathway Herpes virus Viral Multiplication