251 Lab 7

  1. The temperature at which the organism grows best over time is called the _______.
  2. The temperature, below which the organism cannot grow, is called the _______.
  3. The temperature, above which the organism cannot grow, is called the _______.
  4. The turbidity is measured by _______using a _______.
    • absorbance
    • spectrophotometer
  5. The higher the absorbance of light, the higher the growth, i.e., they are ________.
  6. As cells grow (increase in number), more light is absorbed, and the higher the absorbance reading (also referred to as _____ _____).
    optical density
  7. Organisms that grow only below 20o C are classified as ______.
  8. Organisms that live in the the cold but can also grow up to 35oC and slightly higher, are classified as _______. Examples are Mold and some bacteria Pseudomonas. Optimal temperature range of 15 – 30oC, ie refrigeration temp
  9. Microbes that are adapted to temperatures between 15oC and 45oC are classified as _________.Most bacteria living in a symbiotic relationship with humans or are pathogenic to humans are _____since body temperature is 37oC
  10. Organisms growing above 45oC - 80oC are classified as _______.
  11. Microbes growing above 80oC up to 110oC are _____ _____.
    extreme thermophiles
  12. These bacteria generally are mesophiles that can survive exposure to temperatures considerably higher than their maximum growth temperature (up to 70o C or higher) for short periods of time. Although they do not grow at these elevated temperatures.
  13. the movement of water across a membrane?
  14. If the solute concentrations are equal or similar on either side of the membrane, it is an _______environment and water does not move favorably in either direction.
  15. If the environment has very few solutes compared to the cytoplasm, this is called ______. Plants can manage this with their cell wall. No cell wall will swell then burst.
  16. ________environments are those in which the solute concentration is higher in the environment as compared to the cytoplasm. Since water moves toward higher solute concentrations,water will leave the cell.
  17. As the cell loses water from its cytoplasm the cell membrane shrinks away from the cell wall. This process is called?
  18. Many bacteria are not tolerant to salinities of greater that ___%.
  19. ______ are adapted to live and grow only in high salinity (very low water activity).
  20. Extreme halophiles can only grow in __% - __% saline environment.
    • 15
    • 30
  21. _______can survive and grow in slightly higher saline environments than nontolerant bacteria, but the salt is not required for growth. They grow up to __% salinity
    • halotolerant
    • 11
  22. Some microbes tolerate very high sugar concentrations and are referred to as _____.
  23. ________is nonionizing, short, high energy wavelength radiation
    Ultraviolet (UV)
  24. longest wavelength of UV
  25. UV-B
    (280 – 315 nm)
  26. which are the most damaging wavelengths? and have ___-___nm?
    UV-C 100 – 280 nm
  27. pyrimidine dimers
    repeat resulting in cell death
  28. systems to repair damage to DNA caused by UV light.
    SOS system
  29. Several variables are important in the lethal effects of UV light. These include
    • time of exposure
    • distance from the UV light
    • barriers
    • Nonionizing UV light does not penetrate
    • Plastic petri plate lids will deflect all of the UV light
    • Endospores are a barrier
    • Biofilms in nature also provide some UV protection.
  30. Swab the entire surface of the plate, top to bottom and side to side, not missing any areas.
  31. Microbes that rely solely on oxygen as the final electron acceptor to produce ATP are termed?
    strict aerobes.
  32. Microbes that can use oxygen but do not require it but prefer it and grow in its absence are referred to as _____ _____.
    facultative anaerobes
  33. Microbes that cannot grow in the presence of oxygen due to the buildup of toxic metabolites, are ____ ____.
    strict anaerobes
  34. Some microbes are referred to as ______as they can tolerate living in oxygen but do not require it and do not use it for energy production.
  35. _____ bacteria are those that tolerate only small amounts of oxygen.
  36. ____ ___ ___ includes conjugation,transformation,transduction, and use of other mobile genetic elements ,such as transposons.
    Horizontal gene transfer
  37. is a process of transferring genetic information(often in the form of a plasmid, which also contains the information allowing it to be transferred)
  38. information to be transferred from a donor bacterium to a recipient bacterium through a ____ ____.
    sex pilus.
  39. _____are small,circular ,double-stranded DNA molecules that usually exist extra-chromosomally
  40. Transfer of antibiotic resistance genes is common place in the bacterial world and is greatly increased when bacteria exist in a ______,which is common in infectious diseases
  41. Disease resistant
    resistance gene
  42. what structure is most sensitive to UV light in a bacterium?
  43. Image Upload 1
    • 1. strict aerobe
    • 2. strict anaerobe
    • 3. facultative anaerobe
    • 4. microaerophilic
    • 5. aerotolerant
Card Set
251 Lab 7
251 Lab 7