GMS6121 Exam 3 with complete solutions
Examples of acute viral diseases - ANSWER-Common cold caused by Rhinovirus
Diarrhea caused by Norwalk virus
Examples of chronic viral diseases - ANSWER-Genital herpes caused by HSV
Mononucleosis caused by EBV
Examples of lethal viral diseases - ANSWER-Hemorrhagic fevers caused by Ebola and
Marburg
Rabies caused by Rabies virus
Individual viruses exhibit tropism for particular cell types and organs. - ANSWER-
Examples:
HCV, HBV target liver
Rotavirus, norovirus target gut
Definition of a virus - ANSWER-Obligate intracellular parasite comprised of:
1) Nucleic acid genome
2) Capsid protein coat
In addition to a nucleic acid genome and capsid protein coat, some viruses have
______________ - ANSWER-An envelope, a lipid membrane with glycoproteins
provided by the host
,Viruses are intracellular parasites because they lack four key features - ANSWER-1)
Enzymes that produce chemical building blocks
2) Enzyme systems that generate energy
3) Enzymes, tRNAs, and ribosomes that enable protein synthesis
4) Membrane bound organelles
Virion - ANSWER-A complete, single, infectious viral particle
Nucleocapsid - ANSWER-capsid and nucleic acid together
Naked viruses are resistant to - ANSWER-Drying
Heat
Detergents
Acid
Enveloped viruses are sensitive to - ANSWER-Drying
Heat
Detergents
Acid
Naked viruses stability and consequences for immune control - ANSWER-Stability
Remain infectious upon drying
Survive on surfaces and fomites
Survive acidity of GI tract
Consequences for immune control
Must lyse host cells in order to release mature particles
Humoral/antibody response is sufficient to neutralize infection
Enveloped viruses stability and consequences for immune control - ANSWER-Stability
Cannot survive acidity of GI tract
Must remain wet for transmission
Trasmit by droplets and secretions
Consequence for immune control
Don't need to lyse cells in order to release mature particles
Require Humoral and cellular responses to neutralize infection
, Humoral immunity - ANSWER-B cells
Cellular immunity - ANSWER-T cells
Structure of most capsids - ANSWER-Symmetrical or simple
Icosahedral, helical
Size range of viruses - ANSWER-20-300nm
Icosahedral capsids - ANSWER-Formed by assembly of 60 identical proteins.
Three proteins come together to form a complex.
20 faces
Example of naked icosahedral virus - ANSWER-Adenovirus
Example of enveloped icosahedral virus - ANSWER-HSV
Example of naked helical capsid virus - ANSWER-TMV
Example of enveloped helical capsid virus - ANSWER-Measles/paramyxovirus
Purpose of viral genome - ANSWER-1) Carry all virus genes
2) Encode proteins for
- Virus genome replication (ALL)
- Formation of the capsid (ALL)
- Virion assembly (ALL)
- Evasion of intracellular defense system (SOME viruses)
- Evasion of extracellular immune response (SOME viruses)
Baltimore Classification - ANSWER-1) dsDNA
2) ssDNA
3) dsRNA
4) +ssRNA
5) -ssRNA
6) Retroviruses -ssRNA + RT
Examples of acute viral diseases - ANSWER-Common cold caused by Rhinovirus
Diarrhea caused by Norwalk virus
Examples of chronic viral diseases - ANSWER-Genital herpes caused by HSV
Mononucleosis caused by EBV
Examples of lethal viral diseases - ANSWER-Hemorrhagic fevers caused by Ebola and
Marburg
Rabies caused by Rabies virus
Individual viruses exhibit tropism for particular cell types and organs. - ANSWER-
Examples:
HCV, HBV target liver
Rotavirus, norovirus target gut
Definition of a virus - ANSWER-Obligate intracellular parasite comprised of:
1) Nucleic acid genome
2) Capsid protein coat
In addition to a nucleic acid genome and capsid protein coat, some viruses have
______________ - ANSWER-An envelope, a lipid membrane with glycoproteins
provided by the host
,Viruses are intracellular parasites because they lack four key features - ANSWER-1)
Enzymes that produce chemical building blocks
2) Enzyme systems that generate energy
3) Enzymes, tRNAs, and ribosomes that enable protein synthesis
4) Membrane bound organelles
Virion - ANSWER-A complete, single, infectious viral particle
Nucleocapsid - ANSWER-capsid and nucleic acid together
Naked viruses are resistant to - ANSWER-Drying
Heat
Detergents
Acid
Enveloped viruses are sensitive to - ANSWER-Drying
Heat
Detergents
Acid
Naked viruses stability and consequences for immune control - ANSWER-Stability
Remain infectious upon drying
Survive on surfaces and fomites
Survive acidity of GI tract
Consequences for immune control
Must lyse host cells in order to release mature particles
Humoral/antibody response is sufficient to neutralize infection
Enveloped viruses stability and consequences for immune control - ANSWER-Stability
Cannot survive acidity of GI tract
Must remain wet for transmission
Trasmit by droplets and secretions
Consequence for immune control
Don't need to lyse cells in order to release mature particles
Require Humoral and cellular responses to neutralize infection
, Humoral immunity - ANSWER-B cells
Cellular immunity - ANSWER-T cells
Structure of most capsids - ANSWER-Symmetrical or simple
Icosahedral, helical
Size range of viruses - ANSWER-20-300nm
Icosahedral capsids - ANSWER-Formed by assembly of 60 identical proteins.
Three proteins come together to form a complex.
20 faces
Example of naked icosahedral virus - ANSWER-Adenovirus
Example of enveloped icosahedral virus - ANSWER-HSV
Example of naked helical capsid virus - ANSWER-TMV
Example of enveloped helical capsid virus - ANSWER-Measles/paramyxovirus
Purpose of viral genome - ANSWER-1) Carry all virus genes
2) Encode proteins for
- Virus genome replication (ALL)
- Formation of the capsid (ALL)
- Virion assembly (ALL)
- Evasion of intracellular defense system (SOME viruses)
- Evasion of extracellular immune response (SOME viruses)
Baltimore Classification - ANSWER-1) dsDNA
2) ssDNA
3) dsRNA
4) +ssRNA
5) -ssRNA
6) Retroviruses -ssRNA + RT
