text 2.txt

Card Set Information

text 2.txt
2011-05-06 10:31:14
Test Microbiology Chang

Test 2 Dr.Chang
Show Answers:

  1. ´╗┐The sum total of all chemical reactions is known as _____.
  2. Which of the following is correct?
    Vitamins are most commonly required growth gactors and required in small amount.
  3. What are macronutrients?
    • Carbon
    • potassium
    • Nitrogen
    • Sodium
  4. Siderophores help transfer what nutrients across the cell membrane?
  5. What describes culture media correctly?
    • In general, complex media contain yeast extract or meat extract
    • selective media contain compounds that selectively inhibit growth of some microbes, but not others
    • Differential media contain an indicator, usually a dye , that detects particular chemical reactions occur during growth
  6. Sterilization refers to?
    Absence of all microorganisms including viruses
  7. There is a mixture of bacterial culture and a professor asks you to isolate lactose fermenting bacteria. Which of the fallowing media should be used to select lactose fermenting bacteria from the mixed culture and what would you expect to see on that media if lactose fermenting bacteria exist in the mixture?
    MacConkey agar, pink colonies
  8. If lactose fermentation on macConkeys does now exist but only Salmonella are present what ph would you expect to see on that media?
  9. Chemolithoautotrophs use ______ as an energy source and _____ as a carbon source.
    Inorganic compounds, CO2
  10. If delta G is positive _______
    the reaction is endergonic and requires the input of energy
  11. What is true of catalysts?
    It changes reaction rate
  12. What is true of enzymes?
    • They are biological catalysts and increase the rate of chemical reactions
    • They are typically proteins, although some RNAs have enzymatic activity
    • They are highly specific because of active site, the region of the enzyme that binds the substrate
  13. What correctly describes redox reactions?
    In an oxydation reaction occurs , a reduction reaction must also occur
  14. What properly describes NAD+/NAGH reactions
    • They are recycled
    • They facilitate the redox reactions without being consumed
    • NADH dehydrogenase is a protein bound to inside surface of cytoplasmic membrane and its active site binds to NADH
  15. What involves substrate-level phosphorylation to generate ATP
    Phosphoenolpyruvate (PEP) to pyruvate
  16. Net products of glycolysis are 2NADH, 2 ATP, and 2 pyruvates per one glucose molecule and net products of lactate fermentation are 2 NADH, 2 ATP, and 2 lactate molecule per one glucose molecule(T,F)
  17. What is found in gluconeogenesis?
    • PEP-carboxykinase
    • pyruvate carboxylase
    • glucose-6-phosohate
  18. In aerobic respiration what is the terminal electron acceptor?
  19. Alkaliphite Bacillus firmus utilizes ______ to create membrane energetics.
    Sodium motive force
  20. One purpose of the TCA cycle is to generate NADH that will be used in the electron transfer chain. Another purpose of TCA cycle is to make some intermediates that can be used during biosynthesis reactions. (T/F)
  21. Which of the following molecules is part of net products of the TCA cycle?
    • CO2
    • NADH
    • GTP
  22. What correctly describes microbial culture?
    • In a chemostat, the growth rate is controlled by dilution rate
    • in a chemostat the growth yeild is controlled by the concentration of the limiting nutrients
    • In a batch culture, it is impossible to independently control both the growth yeild and rate
  23. In general via aerobic respiration how many ATP can be generated from 1 NADH and 1 FADH respectively?
    3 ATP/ 2 ATP
  24. Organisms that live in the environments high in sugar as solute are called ___.
  25. What is the correct order of transfer of electrons in the ETC.
    FADH2 to quinones to cytochrome bc1 to cytochrome c to cytochromes a and a3
  26. In thermophiles different modifications in cytoplasmic membranes can be observed for Bacteria and Archaea. Bacterial thermiphiles have lipid monolayer rather than bilayer, wherease archaeal thermophiles have lipids rich in saturated fatty acids that form a strong hydrophobic environment than do unsaturated fatty acids.(T/F)
  27. Label these statements as (T/F)-----some microbes can grow in bioling water. Taq polymerase was isolated from a thermiphile and is used in the polymerase chain reaction technique. In gerneral mesophiles that have midrange temperature optima are found in warm blood animals. Mechanisms for combating low water activity in surrounding environments involve pumping internal solutes out to the environment
  28. What statements are true regarding feedback inhibition?
    • Feedback inhibition is a mechanism for turning off the reactions in a biosynthetic pathway
    • In the feedback inhibition, end product of the pathway binds the first enzyme in the pathways
    • Isoenzymes are different enzymes that catalyze the same reaction, but are subject to different regulatory controls
  29. Cryptic growth occurs ____.
    as the number of cells being generated equals the number of cells dying
  30. Direct microscopic counts of natural samples typically reveal for more microorganisms than are recoverable on plates of any giver culture conditions. Why does it happen?
    • Micrscopic methods count dead cells whereas viable methods do not
    • Different microorganisms in even as very small sample may have different requirements for resources and conditions in laboratory culture
    • Viable but non-culturable microorganisms are present
  31. What factors influence microbial growth?
    • PH
    • water availability
    • oxygen
    • temperature
  32. In microbial growth measure which of the following are advantages of turbidity measurements?
    They typically do not require destruction of significant disturbance of samples
  33. What are the limitations of microscopic counts?
    • Cannot distinguish between live and dead cells without staining
    • Debris in samples can be mistaken for cells
    • cell suspensions of low desity are hard to count
  34. The amino group typically comes from inorganic nitrogen source obtained from the environment and is incorporated by glutamate dehydrogenase or glutamine synthetase(T/F)
  35. The major shape-determining protein in prokaryotes is called _____.
  36. which of the following matabolisms utilize electron transport/proton motive force?
    Chemolithotrophy and respiration
  37. Fatty acids are biosynthesized two carbones at a time using a(an) ______ that holds the growing fatty acids as it is being synthesized
    acyl carrier protein(ACP)
  38. In regulation of activity of biosynthetic enzymes, glutamine synthetase is regulated by adenosine monophosphate, which of the following describes correctly?
    The amount of glutamine and GS activity is inversely correlated
  39. In bacterial growth, generation time is dependent on ______.
    growth medium and incubation conditions
  40. What is true regarding the ETC
    • The net result of electron transfer is the generation of a pH gradient and an electrochemical potential across the membrane
    • Oxalacetate is important the formation og phosphoenolpyruvate in gluconeogenesis
    • ATP synthase complex converts proton motive force into ATP
  41. In aerobic respiration, how many NADH are generated by the both glycolysis and TCA cycle per two glucose molecules?
  42. An energized state of a membrane created by a proton gradient and usually formed through action of an electron transfer chain is called _______.