Virus Lecture Exam Flashcards
What are viruses considered?
Obligate intracellular parasites
What are possible things viruses can have?
DNA or RNA
Protein Coat or no Protein Coat
Envelope or No Envelope
Viruses are able to pass through a filter as small as…?
0.2 um filters so find a smaller one to exclude viruses bigger than 0.2um
What are some things viruses lack?
Cytoplasm, cell membranes, ribosomes, other organelles, machinery that produces energy or biosynthetic things for an independent life
What are two kinds of things that are the same size or smaller than a virus?
Viroids and prions
What part of the virus directs the synthesis of viral components by hijacking cellular systems in the host?
viral genome
Define virions
A single infectious virus particle
What are the steps of the virus’ infectious cycle?
- Attachment
- Penetration
- Uncoating
- Replication
- Maturation
- Release - Lysis (ideal) and apoptosis (less than ideal)
What organization is responsible for viral nomenclature?
International Committe on Taxonomy of Viruses (ICTV)
True or false, ICTV, internaltional committee on taxonomy of viruses classify viruses past the species level.
False they do not. They don’t recognize subspecies level of viruses
In viral taxonomy, The order of viruses would have what suffix?
-virales
In viral taxonomy, the family level of viruses would have what suffixes?
-viridae
In viral taxonomy, the subfamily level of viruses would have what suffixes?
-virinae
In viral taxonomy, the genus level of viruses would have what suffixes?
-virus
Describe the baltimore classification
A scheme for classifying viruses based on the type of genome and its replication strategy. The characteristics are viral genome ‘s nucleic acid ( DNA or RNA ), strandedness (single-stranded or double-stranded), Sense, and method of replication determine its class.
What are the 7 groups of baltimore classification?
I: dsDNA viruses (e.g. Adenoviruses, Herpesviruses, Poxviruses)
II: ssDNA viruses (+)sense DNA (e.g. Parvoviruses)
III: dsRNA viruses (e.g. Reoviruses)
IV: (+)ssRNA viruses (+)sense RNA (e.g. Picornaviruses, Togaviruses)
V: (−)ssRNA viruses (−)sense RNA (e.g. Orthomyxoviruses, Rhabdoviruses)
VI: ssRNA-RT viruses (+)sense RNA with DNA intermediate in life-cycle (e.g. Retroviruses)
VII: dsDNA-RT viruses (e.g. Hepadnaviruses)
What are examples of the first group of the baltimore classification?
Group I, double strand DNA viruses. Examples are Adenoviruses, Herpesviruses, Poxviruses
What are examples of the second group of the baltimore classification?
Goup II, single strand DNA viruses that are positive sense. One example is Parvoviruses
What are examples of the third group of the baltimore classification?
Group III, double strand RNA viruses. An example is Reoviruses
What are examples of the fourth group of the baltimore classification?
Group IV, (+) single strand RNA viruses, Positve sense RNA. Examples are picornaviruses and togaviruses
What are examples of the fifth group of the baltimore classification?
Group V, (-) single strand RNA viruses, negative sense RNA. Examples are orthomyxoviruses and rhabdoviruses
What are examples of the sixth group of the baltimore classification?
Group VI, single strand RNA reverse transcript viruses, positive sense RNA with DNA intermediate in life cycle. Examples are retroviruses
What are examples of the seventh group of the baltimore classification?
Group VII, double strand DNA reverse transcript viruses. Examples are hepadnaviruses.
List DNA virus families
H2A2P2P2Y
Hepadnaviridae
Herpesviridae
Adenoviridae
Anelloviridae
Parvoviridae
Papillomaviridae
Polyomaviridae
Poxviridae
What disease or condition can hepadnavirus cause? What can be taken to prevent an infection from the virus?
Hepatitis B, there is a vaccine available to reduce the chance of being infected.
Describe hepatitis B
A hepadnavirus that targets the liver. The infection is usually asymptomatic that can be acute or chronic. The outcomes can be fatal or limiting but the risk of the disease being fatal increases if there is a co-infection with hepatitis D. If the damage progresses the patient may require a transplant.
A patient is tested for Hep B. The patient has HbsAb floating in their system. What does this mean?
Immune system is actively fighting against the virus in other words an active infection.
A patient is tested for Hep B. They have HBsAg and HBeAg only. What does this mean?
Early acute hepatitis B
A patient is tested for Hep B. They have HBsAg, HBeAg, and HBcAb. What does this mean?
The patient has acute or chronic HBV