er Bacteria & Viruses pg 471

Bacteria Eubacteria Archaebacteria Prokaryotes Prokaryotes Cell walls w peptido glycan Prokaryotes Cell walls w/o peptidoglycan pg 472

Identify bacteria Shape Cell walls Movement Energy – where does it originate? pp 473 - 474

Shape Bacilli - rod Cocci - sphere Spirilla - spiral, corkscrew

IMPORTANCE OF BACTERIA Decomposers Nitrogen fixation Human use Industrial, pharmaceuticals, research Our intestines E. coli or Escherichia coli We give: shelter, warm, food supply They give: help with processing foods, make vitamins Pp 476 - 477

Control bacterial growth Sterile heat Disinfectants – kitchen, bathroom, anti-bacterial soaps (not necessarily a good idea) Food storage & processing Refrigeration Cooking food Canning Chemically preserved (salt, vinegar, sugar) honey: nature’s antibacterial pp 487 - 488

Viruses Very small, diverse group Living or not living (figure 19-11) ? pp 478, 483

Virus parts Two main parts: genetic material and protein coat Genetic material = DNA or RNA Protein coat = capsid T4 Bacteriophage Tobacco MosaicVirus Influenza Virus RNA head DNA RNA Capsid Capsid Proteins Tail sheath Tail fiber Surface proteins Membrane envelope pp 478 - 479

Capsid proteins Allow virus to enter host cell Capsid binds to receptors on host cell to “trick” the cell into letting it enter Viruses are highly specific to host cell Plant viruses infect plants bacteriopahges infect bacteria (bacterio = bacteria, phage = eats) Most of the time animal viruses are species specific pg 479

Virus Life cycle Lytic and Lysogenic Cycles Symbiotic relationship? pp 480 - 481

Retrovirus Retro = backwards, backwards virus Genetic material = RNA Mutates more frequently Infects RNA DNA DNA like prophage (dormant) Examples: some cancers, HIV pg 483