Micro Chapter 13 Flashcards
What is a virion?
fully developed infectious particle
What composes a Virus?
- Genome (Usually DNA)
- B Capsid/Coat
What is different about the genetic material in HIV?
RNA not DNA
Describe a virus’s coat
- unique
- used for identification
Describe a virus’s envelope
- composed of protein, phospholipids, and carbs
- made from small piece of host cell’s plasma membrane
What are virus spikes?
entry (hemaglutination) and exit (neuraminidase) mechanisms
In a virus name, what do the numbers represent? For example in H1N1
- number of changes in spike protein
- Hem group and neuraminidase went through one change each
What two types of spikes does HIV have?
- GP41
2. GP120
Describe an HIV virion
- can move around
- two RNA strands
- capsid
- spikes
- enzyme reverse transcription
Why is HIV called a retrovirus?
because of reverse transcription
Describe reverse transcription
- RNA converted to single strand DNA through use of RT enzyme
- New DNA replicated through use of RT enzyme
- Viral DNA penetrates nucleus of host and inserts into existing DNA to create a provirus to continue infection
What is a latent provirus?
provirus is dormant (asymptomatic) for a period of time
An HIV provirus can…
completely change a host cell into a cancer cell called Kaposis Sarcoma (effects blood vessels and skin cells)
Why is the development of a vaccine so hard for HIV?
- mutates almost every time reverse transcription occurs
What cell is most vulnerable to HIV?
CD4
3 Stages of CDC
- CD4 500mm3- lymphadenopathy
- CD4 200-499mm3- fever, diarrhea, shingles, hairy leukoplakia, cervix is precancerous
- CD4- clinical stag, pneumonia. brain degeneration, vision loss (sarcoma)
HIV is transmitted mostly through
- semen and vaginal secretions
While saliva contains HIV there is less risk of transmission because…
there are way fewer HIV particles
What is the Cytopathic Effect?
structural changes in host cell due to viral invasion
- Lytic Infection
- Persistant Infection
- Latent Infection
- Cancer
Describe a Lytic Infection
- acute
- destroys host cell
What is an example of a lytic infection?
influenza
What is a Persistent Infection?
- does not kill cell
What is an example of a Persistent Infection?
- measles can cause brain degeneration and death
- Rubella
What is an example of a Latent Infection?
- Shingles (Herpes-3)
- Cold Sores (Herpes-1)
What are two types of Cancer that demonstrate cytopathic effect?
- Burkits Lymphoma- tumor of jaw caused by Herpes-4
2. Nasopharyngeal
