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How many cell types and organ systems do viruses target? - correct answer ✔✔All of them
Do individual viruses exhibit tropism? - correct answer ✔✔Yes, they favor particular cell types and
organs
What type of parasites are viruses? - correct answer ✔✔Obligate intracellular
What do viruses lack that they must gain from their host? - correct answer ✔✔1. enzymes that produce
basic chemical building blocks
2. enzymes that generate usable energy
3. enzymes, tRNAs, and/or ribosomes that direct protein synthesis
4. membranes that concentrate and localize key molecules
What do ALL viruses have? - correct answer ✔✔nucleic acid
capsid - protein coat encoded by the virus
What do SOME viruses have? - correct answer ✔✔envelope - lipid membrane provided by the host
What is a virion? - correct answer ✔✔a complete, infectious virus particle
How do viruses compare to bacteria? - correct answer ✔✔MUCH smaller
first discovered because of their size, used a filter to screen out bacteria and found pathogenic particles
still present = virus
, What is the basic virus structure? - correct answer ✔✔DNA or RNA + Capsid protein = nucleocapsid
Nucleocapsid = naked capsid virus
Nucleocapsid + lipid membrane, glycoproteins = enveloped virus
What are the differences between naked capsid and enveloped viruses? - correct answer ✔✔Naked
Capsid = resistant to drying, heat, detergents, acid
Enveloped virus = sensitive to drying, heat, detergents, acid
What are the pros and cons of naked capsid virus? - correct answer ✔✔-retain infectivity on drying
-survive well on environmental surfaces
-spread easily via fomites
-can survive acidic environment of GI tract
-MUST kill host cells to release mature virus particles
-Antibody response may be sufficient to neutralize infection
What are the pros and cons of enveloped virus? - correct answer ✔✔-does not need to kill cells in order
to spread
- may require both humoral and cellular immune responses
-can not survive GI tract
-must stay wet during transmission
-transmission in large droplets and secretions
Capsids are usually: - correct answer ✔✔simple = 1-3 proteins
symmetrical