chapt 7

  1. nutrition
    a process by which chemical substance are acquired from the enviroment and used in cellular activities such as growth/metabolism

    nutrients are processed and transformed into chemicals of the cell after absorption
  2. essential nutrients
    any substance that must be provided to an organism
  3. macronutrients
    required in large quanities
  4. micronutrients
    trace elements present in smaller amounts
  5. inorganic nutrients
    a combination of atoms other than c and H
  6. organic nutrients
    contain C and H-present in all living things
  7. microbial cells are made up of these 6 elements

    • carbon 50%
    • hydrogen
    • oxygen 20%
    • nitrogen
    • phosphorus
    • sulfur
  8. heterotroph
    must obtain carbon in organic form

    nutritionally dependent on other living things
  9. autotroph
    self feeder

    not nutrionally dependent on other living things
  10. phototrophs
    microbes that photosynthesize energy from sunlight
  11. chemotrophs
    microbes that gain energy from chemical compounds
  12. photoautotrophs
    • photo-sunlight for energy
    • auto- co2 carbon source
  13. chemautotrophs
    • chemo-inorganic chemical for energy
    • auto- co2 ar carbon source
  14. chemoheterotrophs
    derive both carbon and energy from organic compounds
  15. types of chemoheterotrophs
    • saprobes
    • parasites
  16. saprobes
    • free living microorganisms
    • feed primarily on organic detritus from dead oragnisms
    • decomposers of plant litter,animal matter, and dead microbes
    • include fungi and bacteria
  17. parasites
    derive nutrients from the cells or tissues of a host and cause some degree of damage to the host

    also called pathogens because they cause diease
  18. ectoparasites
    live in the body
  19. endoparasites
    live in organs and tissues
  20. intracellular parasites
    live within cells
  21. obligate parasites
    unable to grow outside of a living host
  22. how does transport happen?
    occurs across the cell membrance  in organisms with a cell wall, the wall is too permeable  to control molecules entrance or exit in the cell
  23. passive methods of transportation
    osmosis, diffusion,facilitated  diffusion

    no energy required
  24. active method of transportaqtion

    requires energy
  25. osmosis
    diffusion of water through a selectivly permeable membrane from an area of more dilution to an area of less dilution
  26. selectivly permeable means
    it allows passage of some molecules but not others
  27. isotonic
    the enviroment  is equal in solute concentration  to the cells internal enviroment

    most stable
  28. hypotonic
    the solute concentration of the external enviroment is lower then that of the cells internal enviroment

    net direction od osmosis is from the hypotonic  solution into the cell

    cells without cell walls swell and can burst -LYSIS
  29. hypertonic
    the enviroment has a hight solute concentration  then cytoplasm

    will force water to diffuse out of a cell

    has high osmotic pressure

    will swivel
  30. diffusion of molecules is determined by
    diffusion of molecules across the cell membranes  is largly  detrmined by the concentration gradient  and permeability of the substance
  31. active transport
    nutrrients are transported against the diffusion/concentraction  gradientb  or in the same direction as the natural gradient but ata rate faster than by diffusion alone

    equires the presence of specific membrane proteins

    requires expenditure of energy
  32. phagocytosis
    cell eating

    amoebas and certain white blood cells ; ingesting whole cells or large solid matter
  33. pinocytosis
    cell drinking

    transport of liquids such as oils or molecules in solution
  34. temperature adaptation
    the range of temperature  for the growth of a given microbial species, they assume the ambiant temperature of thier natural habitat
  35. psychrophile
    a microrganism that has a optimum temperature below 15 and is capable of growth below 0
  36. psychotrophs
    grow slowly in cold but have an optimum temperature above 20
  37. mesophile
    • a organism that grows in intermediate temp
    •  optimum growth 20 to 40
  38. thermophile
    a microbe that grows at temp greater then 45
  39. aerobe
    can use gasous oxygen and posseses the enzyme needed to process toxic oxygen productas
  40. obligate aerobe
    can not grow witout oxygen
  41. facultative anaerobe
    can utilize oxygen-prefers it
  42. microaerophile
    does not grow at normal atmospheric concentration of oxygen but requires a small amount of it in metabolism
  43. anaerobe
    lacks the metabolic  enzyme systems for sing oxygen in respiration
  44. strict or obligate
    lack the enzyme  for processing toxic oxygen and con not tolerate  aniy free oxygen in the immediat enviroment and will die if exposed to it
Card Set
chapt 7
chapt 7