micro - exam 1 material

• list several ways in which microbes affect our lives


  pathogenic, decompose waste, produce fermented foods, chemicals and O2
• what is a microbiome


  group of microbes that live stably on/in humans
• what is normal microbiota


  Collection of acquired microorganisms on/in a healthy human
• what is transient microbiota


  microbes that are temporarily found on human body
• system of nomenclature uses what two names? who made it?

  genus and specific epithet; linnaeus
• what are the three domains

  archaea, bacteria, eukarya
• what is bacteria


  - prokaryotic, unicellular org

  - peptidoglycan cell wall

  - binary fission + flagella
• what is archaea


  prokaryotic

  - no peptidoglycan cell walls

  - live in extreme environments

  - not disease causing

  ie. methanogens, extreme halophiles, extreme thermophiles
• what are viruses


  DNA or RNA

  - surrounded by protein coat

  - need host
• what are multicellular animal parasites


  eukaryotes, multicellular animals

  ie. fungi and protozoa, flatworms + roundworms (helminths)
• what were the observations made by Hooke and van Leeuwenhoek


  Hooke - discovered cells (cell theory)

  van Leeuwenhoek - discovered first microbes
• compare spontaneous generation and biogenesis


  spontaneous generation -

  life arises from nonliving matter; vital force

  biogenesis - living cells come from preexisting cells
• what did spallanzani do for microbio

  boiled nutrient solution in sealed flasks - no growth
• what did virchow do for microbio

  said cells arise from preexisting cells
• what did pasteur do for microbio


  demonstrated microbes are present in air

  fermentation is cause of microbes

  pasteurization
• what are koch's postulates


  demonstrated that specific microbe causes specific disease
• what did ehrlich and fleming do for microbio


  ehrlich - dev synthetic arsenic drug to treat syphilis

  fleming - found first antibiotic (penicillin)
• what are four beneficial activities of microorganisms


  - degradation of dead plants + animals --> recycle chemical elements

  - decompose organic matter in sewage

  - bacteria can clean up toxic wastes

  - bacteria can be used as insect control
• what is biotechnology and what are examples


  use of microbes for practical applications

  ie. prod food and chemicals
• define resistance


  ability of body to ward off disease
• define biofilm

  a thin, slimy film of bacteria that adheres to a surface
• define emerging infectious disease


  new diseases + increase of diseases in incidence
• what are the five groups of different microbes on the basis of preferred temp

  psychrophiles, psychrotrophs, mesophiles, thermophiles, hyperthermophiles
• what are psychrophiles


  cold-loving microbes
• what are psychrotrophs


  cold-loving microbes, btwn 0 and 20-30C, food spoilage (not disease)
• what are mesophiles


  medium, most common, btwn 20-40C; most pathogens, optimal 37C
• what are thermophiles


  heat loving microbes; 50-60C, hot springs + organic compost
• what are hyperthermophiles


  heat loving, >80C
• how and why is pH of culture media controlled

  bacteria produces acid that interrupts own growth --> needs buffers
• what is the importance of osmotic pressure to microbial growth

  plasmolysis can occur in hypertonic environment (out>in)

  -obligate halophile needs high OP

  -faculative halophile tolerates high OP
• name use for the following elements, needed in large amounts: C, N, S, P


  C - structural backbone of organic mol

  N - makes up protein, DNA + ATP

  S - used in AA, thiamine + biotin

  P - used in DNA, RNA + ATP
• what are the classifications of microbes based on oxygen


  obligate aerobes, facultative anaerobes, anaerobes, aerotolerant anaerobes, microaerophiles
• what are obligate aerobes

  require oxygen
• what are facultative anaerobes


  can live with or without oxygen
• what are anaerobes


  unable to use oxygen and most are harmed by it
• what are aerotolerant anaerobes

  tolerate but cannot use oxygen
• what are microaerophiles


  require oxygen concentration lower than air
• describe formation of biofilms and their potential for causing infection


  formed in communities; hard to get rid of (ie. catheters, <3 valves, contacts)
• what is chemically defined media

  exact chemical comp is known
• what is complex media


  nutrient rich but poorly defined