microbio meg test 2

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  1. –Nutrients
    • are acquired from the environment
    • and used for cellular activities
  2. •Essential nutrient:
    any substance that must be provided to an organism
  3. •Macronutrients
    • –Required in relatively large quantities
    • and play principal
    • roles in cell structure and metabolism
  4. •Micronutrients (trace elements)
    • –Present in smaller amounts
    • and involved in
    • enzyme function and maintenance of protein structure
  5. •Inorganic nutrients
    • Simple
    • molecule that contains a combination of atoms other than carbon and hydrogen
  6. •Organic nutrients
    Contain carbon and hydrogen atoms and usually the product of living things
  7. •Growth factor
    • –An organic compound that cannot be
    • synthesized by an organism and must be provided by the environment
  8. •Autotroph
    • “Self-feeder”
    • Organism that uses inorganic CO2 as
    • its carbon source
    • Have the capacity to convert CO2 into
    • carbon compounds
    • Not dependent on other living things
  9. •Heterotroph
    • An organism that must obtain its carbon in organic form
    • Dependent on other life forms
    • Most carbon sources exist in a form that is simple enough for absorption
    • Many carbon sources must be digested by the cell in order to be absorbed
  10. Saprobic
    • Decomposers of plant litter, animal matter, and dead microbes
    • have a rigid cell wall and cannot engulf large particles of food
    • Release enzymes into the environment to digest food
  11. Parasitic
    • Live on or in the body and cause some degree of harm to the host
    • pathogens
    • –Ectoparasites:  live on the body
    • –Endoparasites:  live in organs and tissues
    • –Intracellular
    • parasites: live within cells
    • –Obligate parasites: unable to live outside of a living host
  12. •Diffusion
    • movement of molecules in a gradient from
    • an area of higher density to an area of lower density
  13. •Osmosis:
    • the movement of water across a selectively
    • permeable membrane
  14. •Facilitateddiffusion
    • Mediated transport
    • Utilizes a carrier protein that will bind a specific substance
    • Binding changes the conformation of the carrier proteins so that the substance is moved
    • across the membrane
  15. •Active Transport:
    • Transports nutrients against a
    • concentration gradient or with a concentration gradient at a faster rate
    • Presence of specific membrane proteins
    • Expenditure of energy
  16. •Optimum
    • –Promotes
    • the fastest rate of growth and metabolism
  17. •Singlet oxygen (O)
    • –Extremely reactive molecule produced both by living and nonliving processes
    • –Produced by phagocytes to kill invading microbes
    • –Buildup of singlet oxygen and the oxidation of membrane lipids and other molecules can
    • damage or destroy a cell
  18. •Superoxide ion (O2-), hydrogen peroxide (H2O2), and hydroxyl radicals (OH-)
    • –Destructive metabolic byproducts of
    • oxygen
    • –Cells use enzymes to scavenge and
    • neutralize them
    • •Catalase
    • •Superoxide dismutase
  19. •Aerobe
    • –Can
    • use gaseous oxygen in its metabolism
    • –Possesses
    • the enzymes needed to process toxic oxygen products
    • Obligate aerobe: 
    • an organism that cannot grow without oxygen
  20. •Microaerophile
    • –Does not grow at normal atmospheric
    • conditions of oxygen
    • –Requires a small amount of oxygen
    • in its metabolism
    • -live in a habitat that provides a small amount of oxygen but is not directly exposed to the atmosphere
  21. •Facultative anaerobe
    • –An aerobe that does not require oxygen for its metabolism
    • –Capable of growth in the absence of oxygen
    • –Metabolizes by aerobic respiration when oxygen is present
    • –Adopts fermentation when oxygen is absent
  22. •Anaerobe
    • –Lacks the metabolic enzyme systems
    • for using oxygen in respiration
    • –Strict or obligate anaerobes
    • cannot tolerate free oxygen and will die in its presence
    • •Live in highly reduced habitats
    • such as lakes, oceans, and soil
  23. •Aerotolerant anaerobes
    • –Do not utilize oxygen
    • –Can survive and grow to a limited
    • extent in its presence
    • –Not harmed by oxygen because they
    • possess alternative mechanisms for breaking down peroxides and superoxide
  24. •pH:
    • the degree of acidity or alkalinity of a
    • solution expressed on a scale from 0 – 14
  25. •Obligate acidophiles
    • –Require an acidic environment for growth
    • Molds and yeasts tolerate acid and are common spoilage agents of pickled foods
  26. •Alkalinophiles
    • –Live in hot pools and soils that
    • contain high levels of basic minerals
    • –Bacteria that decompose urine create alkaline conditions
  27. •Obligate Halophiles
    • –Require high concentrations of salt
    • for growth
    • –Have significant modifications to
    • their cell walls and membranes
  28. •Halotolerantor Facultative halophiles
    • –Resistant to salt, even though they
    • do not normally reside in high-salt environments
  29. •Protective measures against radiation
    • –Yellow carotenoid pigments absorb
    • and dismantle toxic oxygen
    • –Other microbes use enzymes to
    • overcome the damaging effects of UV radiation on DNA
  30. Image Upload 1
    biofilm build up
  31. Image Upload 2
    Binary Fission
Card Set
microbio meg test 2
Meagan's second microbio test
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