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Flashcards in Exam 2.1 Deck (186)
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What are 5 possible responses a cell can have to a virus

1. abortive
2. lytic
3. non-lytic
4. latent
5. transformation


What is more hardy, enveloped or non-enveloped virus

non-enveloped because the envelope is sensitive to desiccation


How does a virus get into a cell

Its spike proteins bind to cell receptors


What is a capsid

Protein coat or bottle around the viral genome


What types of capsids can a virus have

helical or icosahedral


What type of genome can a virus have

Either double or single stranded RNA or DNA


What are the 4 viral morphologies

Capsid, envelop, Genetic material including genetic sense, spike proteins


How does the body deal with a virally infected cell

a CD8 killer cell or Natural Killer cell will kill the cell


What is a viral envelop formed from

Normally formed when the virus buds out of a cell, and so is composed of that cell's membrane and viral spike proteins


What are the 2 requirements for viral replication

1. virus must cause the replication of their genetic material
2. Virus must produce (+) RNA to replicate protein components


What 2 things happen to a (+)ssRNA virus when it enters a cell

1. It can be translated immediately into proteins, 1 of which must be RNA-d, RNA-p
2. It must be copied to (-)RNA for synthesis of many (+)RNA strands


What 3 things happen to a (-)ssRNA virus when it enters a cell

1. It must be transcribed into (+)RNA by the RNA-d,RNA-p it brought with it
2. multiple copies of (-)RNA are made from the (+)RNA,
3. some (+)RNA are transcribed into viral proteins


How does a (-)dsRNA virus work

Just like a (-)ssRNA virus. Must bring its own RNA-d,RNA-p


What must all RNA viruses code for

RNA-dependent, RNA-polymerase


What must Retroviruses code for

RNA-dependent, DNA-polymerase (reverse transcriptase)


What is horizontal transmission

person to person


What is vertical transmission

Mom to fetus transplacentally or to baby during birthing


What is a carrier

Chronically infected, asymptomatic individual


What is the iceberg effect

Reference to how many infected people are asymptomatic


If antimicrobial defenses are intact, how do microbes infect an individual

1. Microbial attachment/penetration 2. biting arthropod 3. skin wound/animal bite


If antimicrobial defense are not intact, how do microbes infect an individual

They just waltz right in


What is the public health consequence of a disease with a large iceberg effect

It makes spread of the disease much more likely since asymptomatically infected individuals are still infectious, but can't be isolated


What is a recurrent illness

One you never get rid of, like Herpes


What happens if the number of microorganisms exceed the disease threshold in an individual

Then the individual will display disease symptoms. Until this threshold is reached, the individual will display no signs or symptoms


Disease potential =

(virulence)(dose)/host resistance


Which antibody do humans make the most of

IgA; more than all the other antibodies combined


How does IgA from an infection at a particular site get to another site

multiplying daughter B-cells migrate to other mucosal sites


How does IgA get presented on a mucosal surface

It binds to a poly-Ig Fc receptor on the basolateral side, which is then taken up by epithelial cells and extruded to the outer or lumen-surface


What is the role of poly-Ig Fc receptor

It tags IgA for uptake and secretion by epithelial cells and a portion of it remains attached to IgA to help it resist proteases


What is the role of IgA

Block colonization by binding fimbrae; neutralize by covering spike