Week 7 Review Worksheet Key PDF

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Weekly Review Assignments Based on Lecture
Dr. Schroeder...

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BILD 2 Schroeder Section B01 Week 7 Worksheet Key L11: HIV/ AIDS 1. HIV is a retrovirus. What does this mean? - Virus uses RNA to store its genetic material, thus upon infection Reverse Transcriptase is required to convert RNA into DNA in order to successfully infect the host cell. 2. Complete the table Step 1. Binding and Entry

2. Reverse Transcription

3. Integration into host genome 4. Activation

5. Assembly 6. Budding

Description HIV binds to the T helper cell (mediated by gp120/gp 41) and fuses to the host cell membrane. The viral capsid is released into the host, the capsid is degraded and the viral genome and the 3 enzymes (Reverse transcriptase, Integrase, Protease) are released. RT synthesizes viral DNA from RNA (reverse transcription occurs twice – synthesis of second complementary DNA) DNA translocate into the nucleus. Integrase incorporates viral DNA into the host genome Viral DNA is transcribed into viral mRNA. Viral RNA migrates to the cytoplasm where the host cell machinery synthesizes viral protein. Protease cleaves proteins (gag, pol, and env). Genomic RNA and proteins get assembled to form a new virus. New viruses bud off the cell using the host cell membrane and are free to infect other cells.

3. What immune cells does HIV target? How does this affect the ability of the immune system to fight infection? - HIV targets CD4 T cells (aka Helper T cells). By targeting and infecting CD4 T cells, HIV eventually kills the CD4 T cells (cells eventually die because of excessive budding). The decline in CD4 T cells diminishes the capacity of the immune system to fight infection, as the CD4 T cells are responsible for secreting signals that mobilize and activate other immune cells. Because of its crucial role, HIV infected individuals are vulnerable to opportunistic infections (infections that would otherwise be nonlethal to a healthy individual).

BILD 2 Schroeder Section B01 4. Matching __A__Initial infection/ incubation __C__Acute Infection __D__Clinical Latency __B__AIDS

A. No symptoms, can last for weeks to years B. CD4 cells count...