micro exam 3 part 2

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micro exam 3 part 2
2011-07-07 16:39:20
micro exam part

micro exam 3 part 2
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  1. What diseases or conditions are caused by Epstein-Barr virus?
    • a. Burkitt’s lymphoma
    • b. Nasopharyngeal carcimona
    • c. Infectious mononucleosis
  2. What are the facts about virods?
    Have circular ssRNA molecules that lack a Capsid and cause a variety of plant diseases.
  3. What diseases are caused by prions?
    Kuru (found only in the Fore, an eastern New Guinea tribe that practice ritual cannibalism),Creutfeldt-jakob disease (CJD), fatal familial insomnia, and Gerstmann-Strassler-Scheinker Syndrome (human diseases).
  4. What type of NA viruses make up most of the plant viruses?
    Most plant viruses are RNA, plus strand are most common.
  5. What is the most common functioning molecule of animal virus receptor?
  6. What type of virus causes T-cell leukemia?
    T-cell lymphotropic viruses (HTLV-1 and HTLV-2)
  7. What methods do viruses enter host cells?
    • 1. Fusion of the viral envelope with the host cytoplasmic membrane results in deposition of the Nucleocapsid core within the cell.
    • 2. Endocytosis; lysosomal enzymes and low endosomal pH often trigger the uncoating process.
  8. What are the mechanisms that viruses can cause cell damage to the host cell?
    • 7 mechanisms
    • 1. Inhibition of host DNA, RNA, and protein synthesis.
    • 2. Lysosome damage, leading to release of hydrolytic enzymes into the cell.
    • 3. Plasma membrane alteration, leading to host immune system attack on the cell or leading to cell fusion.
    • 4. Toxicity from high concentration of viral protein.
    • 5. Formation of inclusion bodies that may cause direct physical disruption of cell structure.
    • 6. Chromosomal disruptions.
    • 7. Malignant transformation to tumor cell.
  9. What is the mechanism that prions use to cause abnormality?
    PrP (proteinaceous infectious particles) by abnormal PrP causing prion disease by inducing a change from the normal conformation of the cellular PrP to the abnormal form.
  10. What are the characteristics of macrophage?
    Where are they derived?
    • 1. Larger than monocytes, have more organelles that are critical for phagocytosis, have a plasma membrane covered with microvilli and possess receptors that allow them to discriminate self from nonself; surface molecules recognize common components of pathogens (LPS) respond to Opsonization (chemical enhancement of phangocytosis)
    • 2. From monocytes.
  11. How does the complement system aid the defensive response of an organism?
    Lysis of target cells, attraction of phagocytic cells, activation of phagocytic cells
  12. How does the complement system aid the defensive response of an organism?
    Lysis of target cells, attraction of phagocytic cells, activation of phagocytic cells
  13. What types of immunity does the alternate complement pathway play an important part?
    The innate, nonspecific immune defense against intravascular invasion by bacteria and some fungi
  14. What is the function and characteristics of dendritic cells?
    Play an important role in nonspecific resistance by killing viruses, by secreting interferon-a; mature Dendritic cells migrate to blood stream or lymphatic system where they interact with B-cells, natural killer cells, and present foreign antigens to T cells.
  15. What must opsonizing antibodies do to stimulate phagocytosis?
    Prepare organism by coating it with a serum, binding proteins, or glycoprotein that prepare them for recognition and ingestion by phangocytic cells.
  16. What triggers a fever response?
    Fever helps host’s defense by doing what?
    • 1. A disruption in the hypothalamic regulatory control, leading to increase of thermal “set point”.
    • 2. Stimulating leukocytes to destroy microorganisms, Enhances specific activity of the immune system, and enhances microbiostatsis (growth inhibition) by decreasing available iron to the microorganism.
  17. What type of cells release hisamine?
  18. What type of cells makeup the lymphocytes?
    T-cells, B-cells, and Null-cells ( which include special cells called natural killer or NK cells.
  19. What is the microbiota of the skin found?
    Most skin bacteria are found on superficial cells, colonizing dead cells, or closely associated with the oil and sweat glands
  20. What is the key role(s) or functions of cytokines?
    Stimulate cells to mature and differentiate, produce new effector products, and cause some cells to die. They are also necessary for the immunoregulation of both nonspecific immunity and specific immunity. Come from the T cells.