Virology

Question 1

What is the size range of a virus?

Answer 1

20-250nm

Question 2

What are the 3 main components of a virus?

Answer 2

Nucleic acid
Protein capsid
Lipid envelope (sometimes)

Question 3

What are the gemone sizes for RNA viruses and DNA viruses?

Answer 3

RNA - 5-30kb

DNA - 3-200kb

Question 4

What are the shapes of capsids?

Answer 4

Icosahedral or helical

Question 5

What are the 6 stages in a virus’ life cycle?

Answer 5

Attachment - Cell surface receptor
Entry - Endocytosis, fusion
Uncoating - Enzymatic degradation of proteins
Replication of nucleic acids/proteins - hijacks cell machinery
Spontaneous assembly
Release - Budding, lysis

Question 6

What is special about retroviruses?

Answer 6

they are +ve sense RNA viruses which use reverse transcription to convert into ssDNA before dsDNA and then get transcribed into mRNA

Question 7

What are the main effects of viruses on cells?

Answer 7

Cell lysis
Chronic infection - no cell death with virus replicating
Latency
Transformation - incoorporation of viral genome into host (usally cancerous)