Biomedical Core

The flashcards below were created by user faulkner116 on FreezingBlue Flashcards.

  1. A virus must replicate with in
     a host cell.
  2. The virus provides the ______ or ______ to replicate, and the host cells provide the _______ and _______.
    RNA; DNA; energy; resources
  3. Viruses contain RNA __ DNA
    or; not both

    RNA viruses also contain code for reverse transcriptase, enzyme which makes DNA from RNA.
  4. Viral Structure contains
    Nucleic acid (RNA or DNA)


  5. Capsid is
    a protective coat enveloping the nucleic acid. 

    Determines the shape of the virus.
  6. Capsids are composed of individual protein subunits called
  7. Capsids can be helical, ________, or in some cases ______-________. The combined capsid/nucleic acid arrangement is called the __________.
    polyhedral (multi-sided); bullet-shaped; nucleocapsid.
  8. Envelope are
    are external to the capsid, and are acquired from the combinations of proteins, lipids, and carbohydrates found in the membrane of the host cell.

    present in some viruses.

    • may have glycoprotein spikes.
    •    - determine host cell specificity.
    •    - may hide virus from host's immune system.
  9. What are the five step replication cycle?
    • 1. Adsorption
    • 2. Penetration
    • 3. Synthesis
    • 4. Maturation
    • 5. Release
  10. What happens in the Adsorption step?
    Attachment of the virus to the host cell. 

    Naked (non-enveloped) viruses attach to specific molecular sites on the cell surface.
  11. What happens in the Penetration cycle?
    Virus enters the host cell through endocytosis or fusion and uncoats (takes off its envelope and capsid)
  12. What happens in the Synthesis step?
    This process produces new genetic material and varies between the RNA and DNA viruses.
  13. What happens in the Maturation step?
    is the assembly, or "packaging" of the newly synthesized molecules into complete virons.
  14. What happens in the Release step?
    Departure of new virons from host cell.

    Host cell may rupture or Host cell remains intact and releases the virus.
  15. There are several types of viral infections that fall into two main categories. What are the categories?
    Acute Infections

    Latent/Persistent Infections
  16. Acute infections
    Disease cycle is relatively short.

    Host cell ruptures and virus spreads to neighboring cells. (common cold (rhinovirus), influenza (types A and B), some hepatitis viruses).
  17. Latent/Persistent Infections
    Virus becomes relatively inactive but reemerges.

    Provirus remains in host cell and replicates new virions when "triggered" by some external event such as stress, fever, or other factors.

    Herpes virus, Epstein-Barr virus, Human Immunodeficiency virus (HIV), Cold sores
  18. Immune System Viruses
    Epstein-Barr, HIV
  19. Oncogenic Viruses
    Possess oncognenes (cancer-causing genes) that cause uncontrolled and abnormal division of host cells by altering cell cycle "checkpoints".

    Hepatitis B, Hepatitis C

    Human Papilloma Virus
  20. Viruses such as the human papillomavirus have been directly linked to
    cervical cancer in women.
  21. Treatment of Viral Infections:
    Antibiotics are
  22. Treatment of Viral Infections:
    Antiviral drugs
    slow down attachment of virus to host cell

    suppress, do not cure, viral infection.
  23. Treatment of Viral Infections:
    Salk-Sabin (Polio)

    Gardisil (Human Papilloma Virus-----> cervial cancer)

    Hepatitis A, Heptovax (Hepatitis B)
  24. Substances produced by the host cell such as interferon
    inhibit viral activity.
Card Set:
Biomedical Core
2012-12-11 02:45:05

Objective 14
Show Answers: