Virus II

Question 1

What an example of Eukaryotic Viruses

Answer 1

-retrovirus: HIV- AIDS
-+ strand RNA virus: polio + coronavirus
- - strand RNA virus: Ebola + influenza

Question 2

What is the difference in virus in bacteria cells and animal cells?

Answer 2

-rigid bacterial cell walls: viral genome injected into the cell leaving the coat on the outside
-no cell wall + animal cell: viruses take place via endocytosis

Question 3

Describe retroviruses: HIV

Answer 3

-integrate into the host genome
-replicate via a DNA intermediate. Reverse transcriptase stored in virion
-have lipid bi-layer b/x they take a little membrane w/ them
-envelope proteins get stuck on membrane allowing virus to infect another cell

Question 4

what is reverse transcriptase

Answer 4

RNA -> complementary DNA -> RNA:DNA hybrid -> double stranded DNA

Question 5

What is the pathway of reverse transcription

Answer 5

travel to nucleus -> integrate into host DNA

Question 6

What does HIV do to the cell

Answer 6

-attack Th cells
-replicates in monocytes + Thcells
- Th cells decrease over years, therefore increase sensitivity to opportunistic infections
-gp120 of HIV attaches to CD4 receptor on host cells

Question 7

How are negative strand RA viruses translated

Answer 7

negative strand is complementary to mRNA + must be converted to + stranded RNA by an RNA polymerase before translation

Question 8

How is positive-strand RNA viruses translated

Answer 8

positive strand genomes are similar to mRNA + can immediately be translated

Question 9

How does negative strand viruses spread: rabies, ebola, influenze

Answer 9

-replication starts in the nucleus of the host cell
1) nucleocapsid migrates to the nucleus
2) RNa transcribed to positive strand RNA
3) transcription is accomplished by viral endonuclease + replicate
4) poly-A-tail are added to viral mRNAs + transported out of nucleus

Question 10

How does positive strand RNA viruses spread: Polio, hepatitis A, corona virus

Answer 10

-very small, single stranded RNA
- replication happens in cytoplasm of host cells: b/c similar to mRNA

Question 11

what does the spike protein of SARS-CoV2 target

Answer 11

spike protein targets the cell receptor ACE2

Question 12

What is ACE2 in SARS-CoV2

Answer 12

-surface of epithelial cells in lungs, heart, blood vessels…
- on lungs heavy on alveoli (grape- looking sacks on lungs)
- important for regulating blood pressure, wound health, and inflammation

Question 13

What is TMPRSS2 in SARS-CoV2

Answer 13

-cleaves SARs-CoV2 spike to allow viral entry