Smallest, most common, single-celled organisms that lack a nucleus Archaebacteria Eubacteria EUBACTERIA ARCHAEBACTERIA live everywhere Some cause disease Cell wall: peptidoglycan Example: Escherichia coli Cell wall: not peptidoglycan Typically do not cause disease Example: methanogens (produce methane gas) SHAPES FORMATIONS Bacilli Rod-shaped Cocci Spherical-shaped Spirilla Spiral-shaped Strepto = chains Staphylo = grape-like clusters Get energy by consuming organic molecules made by other organisms CHEMOHETEROTROPHSPHOTOHETEROTROPHS Take in organic molecules for energy and a supply of carbon Example: humans Photosynthetic (use light for energy) but need to take in organic compounds as carbon source Make own food from inorganic molecules Use light energy to convert carbon dioxide and water to carbon compounds and oxygen Example: cyanobacteria Make organic carbon from carbon dioxide and get energy from chemical reactions involving ammonia, hydrogen sulfide, nitrites, sulfur, or iron Example: bacteria in deep ocean BINARY FISSION CONJUGATION When reaches max. size, replicates DNA and goes through mitosis No exchange of DNA material A hollow bridge forms between two bacteria that allows genes to travel from one cell to another When conditions are unfavorable, spores form and lie dormant for months until conditions are favorable again. Some are resistant to heat, dryness, and lack of nutrients. Decomposers helps environment recycle nutrients into soil for use by other organisms Nitrogen fixers convert nitrogen gas into a form plants can use Human uses: food production and digestion (symbiotic relationship), oil spill clean-up Damage cells and tissues of infected organisms directly by breaking down the cells for food Example: Mycobacterium tuberculosis Release toxins (poisons) that travel throughout the body interfering with the normal activity of host Example: Streptococcus Compounds that block the growth and production of bacteria Can be used to cure many diseases and prevent infections Sterilization by heat exposure to high heat for extended period of time Example: pasteurization Disinfectants chemical solutions that kill pathogenic bacteria Food storage and processing Refrigeration, cooking, preservatives Particle of nucleic acid, protein and in some cases, lipids. Enter living cells and use the machinery of the infected cell to produce more viruses. DNA or RNA core Protein coat called capsid Includes proteins that bind to receptors on a cells membrane and trick it into allowing it to enter Viruses that infect bacteria A virus enters a cell, copies itself, and causes the cell to burst. Host cell is lysed and destroyed. Steps: Bacteriophage injects DNA into cell Cell copies viral DNA and parts Parts assembled into new viruses and cell bursts open Host cell makes copies of virus indefinitely. Viral genetic information (prophage) integrates its DNA into DNA of host Viral genetic info replicates with hosts for several generations Prophage can exit host cell at any time and enter lytic cycle. Viruses that contain RNA as genetic info Get name b/c genetic info is copied backwards; from RNA into DNA Example: HIV DNA or RNA core & capsid, no cell membrane Reproduce only in host cell No growth or development Do not obtain or use energy Do not respond to environment A preparation of weakened or killed pathogens Sometimes causes the body to produce immunity to the disease Viruses produce diseases by disrupting the bodys normal equilibrium Some kill cells (poliovirus) Some change growth and development of cells (warts)