Viral Infection 🗸

Question 1

Structure of Viruses

Answer 1

contain either DNA or RNA
capsid made up of repeated subunits of a virally encoded protein
can have icosahedral or helical symmetryis

Question 2

icosahedral symmetry

Answer 2

virus consists of repeated subunits that make up equilateral triangles arranged in a symmetrical fashion

Question 3

helical symmetry

Answer 3

made up of a single repeated unit

Question 4

seven step method of viruses

Answer 4

viral replication
attachment - interact with specific receptors in target cell
entry - endocytosis
uncoating - viral nucleic acid released from capsid
nucleic acid and protein synthesis - host ribosome used to produce new viral proteins
assembly - nucleic acids and proteins packed together
release- budding or lysis

Question 5

budding release

Answer 5

viruses released with envelope derived from host cell membrane, doesn’t kill cell

Question 6

lysis release

Answer 6

virus accumulates until cell blurts, killing the cell

Question 7

pathogenesis

Answer 7

cell death due to lysis
cell death due to immune system
cell proliferation - cancer

Question 8

immune response

Answer 8

cytotoxin T lymphocytes - recognise foreign cell surface proteins, signal to infected cell to commit suicide
neutralising antibodies IgG and IgM

Question 9

viral persistance

Answer 9

viruses may become quiescent - no active replication (may reactivate after a period of latency)
viruses may remain continually active for years - chronic infection