Tutorial Notes

Card Set Information

Tutorial Notes
2015-09-22 01:19:46
microbiology first exam
Micro lecture exam 1
Notes from friday tutorial
Show Answers:

  1. T or F: fungi and plants do not share a cell wall
  2. What are the 4 postulates?
    • 1. Organism present in unhealthy host
    • 2. Organism must be isolated
    • 3. Infect healthy organism¬†
    • 4. Host must be sick with specific disease
  3. Why didn't the postulates work with HIV?
    • HIV stops immune response, which produces different types of illnesses
    • Cannot be isolated
    • Cannot inject into another human being
  4. What are the 4 modern cell theories?
    • 1. all organisms made of living cells
    • 2. all cells made of preexisting cells
    • 3. all biochemistry rxns must occur within a cell
    • 4. all cells have herdity information
  5. How are all cells similiar? (5 ways)
    • 1. all carry DNA
    • 2. have similiar chemical rxns
    • 3. have an external plasma membrane
    • 4. all take in nutrients and create wastes
    • 5. all grow and reproduce
  6. Fill in the blanks:
    1. ___ has a nucleus, ____ has a nucleoid
    2. ____ has a liniear chromosome, ____ has a spiral chromosome
    3. ____ uses mitosis, ____ uses binary fission
    4. ____ has plasmids and endospores, ____ has organelles
    • 1. euk, prok
    • 2. prok, euk
    • 3. euk, prok
    • 4. prok, euk
  7. T or F: both euk and prok cells have cytoplasm and a plasma membrane
  8. Does a gram positive or negative have a thick peptidoglycan layer?
    Gram positive peptidoglycan layer
  9. Does gram positive or negative have an outer membrane?
    gram negative
  10. T or F: gram positive produces endotoxins
    False: gram positives produces exotoxins
  11. Why is it important to know if a bacteria is gram + or - when treating with antibiotics?
    Antibiorics can kill a patient if treated too aggressively because the type of toxins released by the killed bacteria can kill someone in high concentrations.
  12. Where is the periplasmic space?
    space between the cell wall of a bacteria and plasma membrane
  13. In this "space" is where ATP synthesis occurs in bacteria
    Periplasmic space
  14. How can we differ bacterial ribosomes vs. euk. ribosomes?
    prok ribosomes spins differently in a centrifuge than euk
  15. This is where genetic material is housed in prok.
  16. What is the inclusion body?
    granulars of organic and inorganic body that the cell uses to get rid of theparticles
  17. What is the benefit of capsules?
    can help resist phagocytosis
  18. What is the "f-factor"?
    • a way for bacteria to pass on genetic information to another bacteria
    • ¬†- Plasmids are the most successful way
  19. T or F: endospores are only found in gram positive cells
  20. What is the endosymbiosis theory?
    • Life went from a single cell organism to a multicellular one
    • > life did not come from a spark, but from the sun's released energy
  21. What are the arguements that viruses are not alive?
    • 1. they do not eat or produce waste by themselves
    • 2. most or least evolved life forms
    • 3. cannot produce outside of host cell
  22. T or F: all viruses have capsids
  23. What are the properties of viral capsids? (3)
    • 1. molecules in capsids allow virus to find or be taken into a cell
    • 2. they are host specific
    • 3. it gives the virus its shape
  24. How can a virus exit or enter a cell through exocytosis?
    some viruses have envelopes, a membrand around the virus which allows the virus to exit or enter the cell
  25. This process is how a protein is made
  26. What are the two ways a virus is released from a host cell
    • 1. naked virus is when cell is lysed
    • 2. envelope virus is when it creates another membrane from cell and leaves via exocytosis
  27. What are mechanisms of how viruses damage their hosts? 8 in total
    • 1. inhibit host cell's protein synthesis
    • 2. process lysosomes, which contain hydrolitic enzymes, damaging the cell when released
    • 3. alters plasma membrane in such a way that it can no longer bring in food or release waste
    • 4. creates high concentrations in deadly levels of viral proteins
    • 5. formations of inclusion bodies which disrupts cell's chemistry
    • 6. disrupt chromosomes by injecting viral DNA into host RNA
    • 7. transforms a cell to replicate uncontrollably, like a cancer cell
    • 8. makes cell more susceptible to other infections, weakend system
  28. What are prions?
    protonacious particle that acts like a protein. When it comes in contact with a healthy protein, it changes the shape of the healthy protein, which then loses its function.
  29. What are the pros and cons of a counting chamber?
    • Pro: accurate, low tech and cheap
    • con: tedious, has to be stained to differentiate between life and death cells
  30. What are electronic counters used for? What are its pros and cons?
    • Used for RBC & WBC
    • Pro: can easily count small structures
    • con: if sample is not clean, it will count foreign substances
  31. When is viality counting methods used?
    Only when looking at live cells
  32. What are the pros and cons of the membrane filter technique?
    • Pro: can be used in water filtration systems, when taking in large quantities of water
    • con: catches bacteria, but still have to grow the bacteria in a lab after isolating it.
  33. What are ways to culture viruses? 5 ways
    • 1. putting in embryonic eggs
    • 2. putting in tissue culture and flasks
    • 3. euk. cells./??
    • 4. bacteriahage cultivation
    • 5. plant viruses
  34. What are two ways to see if a cell is infected by a virus?
    • Plex: when u see holes in a culture, it shows a lysed cell
    • Cytopathic effects: when cell looks sick or does not behave correctly
  35. What is the trick when looking for bacteriophage in a flask?
    • It is a delicate procedure because, if the virus is thrown in too early, it will lyse all the bacteria before the bacteria can grow in high enough amounts
    • If thrown in too late, the viruses will all have a host and there will be no more isolated viruses