World of Viruses: Midterm – Flashcards

Unlock all answers in this set

Unlock answers
question
5' cap
answer
A cap on the 5' end of mRNAs. Discovered by A.J. Shatkin and B. Moss in 1975. Important for translation.
question
?X174
answer
An ssDNA virus with a circular genome.
question
A.E. Smith
answer
In 1984, discovered nuclear localization signals.
question
A.J. Shatkin and B. Moss
answer
In 1975, discovered 5' caps of mRNAs in reovirus and vaccinia virus.
question
Achilles
answer
A Spartan who fought in the Trojan wars. He was killed by the brother of Hector, from an arrow to the heel.
question
Acidianus bottle virus
answer
A virus, 230 nm long, 75 nm wide. Affects archaebacteria hosts.
question
Acylation
answer
A post-translational protein modification. Addition of lipid components to the polypeptide. Makes a protein hydrophobic.
question
Adenoviridae
answer
A family of isometric viruses. 80 - 110 nm in size. Includes fowl adenovirus 8.
question
Adenovirus
answer
A genus of dsDNA viruses with a linear genome. Affect birds. Has isometric symmetry, T = 25. Has twelve pentons, each composed of 5 protomers. Has twelve hexons per triangular face, for a total of 240, each composed of 3 protomers. Has fibres which are receptors for cells. Can be used to make vaccines. Inhibits the immune system response of apoptosis.
question
Adolf Mayer
answer
In 1886, asked if tobacco mosaic disease was caused by an infectious agent. Used his tumb to transfer the virus from a diseased plant to a healthy plant, causing it to become diseased.
question
Alex Carrel
answer
Grew organs in rich media. Won a Nobel Prize in 1912. Had problems with contamination; competition between virus and bacterial or fungal contaminations.
question
Alfred Hershey and Martha Chase
answer
In 1952, proved that DNA was the genetic material for bacteriophage T2. Blended phage T2 to demonstrate that labelled DNA but not labelled protein entered bacteria to initiate virus ifnection.
question
Alice Woodruff and Ernest Goodpasture
answer
In 1931, grew fowlpox virus on the chorioallantoic membranes of chicken embryos. The poxvirus resulted in thickening of the membrane, resulting in distinct pocks on the membranes; each pock is one viral infection. Allowed for testing of Koch's postulates for viruses. Studies extended to growth of vaccinia and herpesvirus in chicken embryos or tissues.
question
Alimentary tract
answer

Gastrointestinal

A portal of entry. The virus is eaten. Poliovirus, norovirus, and diarrhea can infect through this point.

question
Ambisense
answer
A virus with part of the genome is +RNA, and part of the genome is -RNA.
question
American Revolutionary War
answer

1775 - 1776

A war between America and Britain. The British army held Quebec from American invasion due to smallpox. False British maps were used to trick Americans into thinking their march would be shorter, and winter weather caused many soldiers to go AWOL or die from harsh conditions.

question
Amino acid
answer
A type of molecule. There are 20, with functional groups providing chemical characters such as charge and polarity.
question
Animal viruses
answer
More difficult to work with because animals are expensive, the virus many need specific tissues, there may be other diseases, nutritional problems, or latent infections, as well as ethical issues.
question
Anthrax
answer
A disease caused by bacteria which affects cattle. Robert Kock discovered their endospores.
question
Antonie van Leeuwenhoek
answer
A Dutch scientist from 1683 who invented a high resolution light microscope with excellent visual acuity. Described "little animalcules" in water droplets.
question
Anus
answer
A portal of entry. HPV and HIV can infect through this point.
question
Apoptosis
answer
A defense mechanism of the cell against the virus, but it can be caused by the virus in order to replicate itself.
question
Arenavirus
answer
A genus of negative RNA viruses.
question
Arterivirus
answer
A genus of positive sense RNA viruses.
question
Arthropod borne
answer
Intravenous vector borne. Yellow fiver virus, West Nile virus, and Eastern equine encephalitis virus can infect through this point.
question
Arthur Kornberg
answer
In 1967, generated the ?X174 genome with purified enzymes and viral DNA template.
question
Asfarivirus
answer
A genus of dsDNA viruses.
question
Assembly
answer
The fifth sequelae of virus replication. There is self-assembly of viral nucleic acids and proteins.
question
Astrovirus
answer
A genus of positive sense RNA viruses.
question
Attachment
answer
The first sequelae of animal virus infection and virus replication. Common to all viruses. The virus attaches to a cell receptor. Receptors can be highly specific or highly generalized. Viruses can infect cells with the receptor, and cannot infect cells lacking the receptor. Viruses cannot infect cell in which the virus was removed, or treated with antibodies of the receptor. Viruses can infect cells into which the receptor was introduced by transformation. The more the amount of virus, the more likely that attachment will occur.
question
Autism
answer
It is not correlated with vaccines.
question
Avian influenza virus
answer
A virus. During attachment, it recognizes ?2, 3 linkage between sialic acid and galactose.
question
Axial rise (p)
answer

The raise in height between each subunit.

P = ? ? p

question
Bacterial virus
answer
Research is cheap, and they are easy to grow and handle.
question
Bacteriophage
answer
A virus with a tail structure; it is a combination of helical and spherical structure.
question
Bacteriophage lytic cycle
answer
Cell receptor and phage interaction is very specific, sometimes strain specific.
question
Bacteriophage replication
answer

Has three stages: eclipse phase, maturation, and latent phase.

1. Attachment to host cell receptor

2. Localized lysis with viral lysozymes, and penetration and injection of virus DNA into the cell

3. Early mRNA is transcribed and viral enzymes are syntehsized

4. Nucleic acid replication

5. Late mRNA syntehsis

6. Late protein synthesis

7. Formation of empty precapsids

8. Assembly and DNA packaging of precapsids

9. Lysis of cell wall with viral lysozymes

10. Release of viral particles through the rent in the wall

11. Infection of adjacent cells, repeating the lytic cycle

question
Baculoviurses
answer
Viruses that affect insects.
question
Baltimore classification
answer
Classification of viruses based on nature of their genomes and mRNA synthesis.
question
Bangalali Youngi
answer
An Ebola survivor from Liberia in 2016; this marked Ebola transmission as no longer a global health risk.
question
Baozhong Meng
answer
A professor at University of Guelph doing research on grapevine stem pitting disease virus.
question
Beet curly top virus
answer
A virus in the family Geminiviridae. Affects beets and tomatoes.
question
Beluga whale coronavirus
answer
A positive sense ssRNA virus in the family Coronaviridae. Genome is 31.7 kb.
question
Binomial nomenclature
answer
The species and genus of a living organism.
question
Biosynthesis
answer
The fourth sequelae of virus replication. Viral nucleic acids and proteins are synthesized. Includes transcription, translation, and replication.
question
Birnavirus
answer
A genus of dsRNA viruses with a linear, segmented genome.
question
Bornavirus
answer
A genus of negative sense RNA viruses.
question
Bronchiolitis
answer
Inflammation of the small airways. Can be caused by RSV.
question
Budding
answer
The method of release of enveloped viruses. The virus buds through the endoplasmic reticulum, Golgi body, or plasma membrane. The cell membrane becomes the viral membrane surrounding the nucleocapsid.
question
Bunyavirus
answer
A genus of negative sense RNA viruses with a linear, segmented genome.
question
Calicivirus
answer
A genus of positive sense RNA viruses.
question
Camelpox virus
answer
A virus that affects pigs and camels.
question
Capillary
answer

Drug injetion

A portal of entry. HIV, rabies, and flaviviruses can infect through this point.

question
Capsid
answer

"Box"

A component of the nucleocapsid. A hollow protective protein shell surrounding the core. Composed of capsomeres which self-crystallize into the capsid's final shape and size. The nucleocapsid morphology and symmetry is based on the nature of capsid protein interactions. Its structural integrity depends on the environment. Helps assemble the genome. Protects the genome outside of the cell, and dissociates inside the cell to release the genome. In naked viruses it is needed for attachment to cell receptors, indicating host specificity.

question
Capsid protein (C)
answer
A component of the Zika virus virion. Forms the icosahedral capsid.
question
Capsomere
answer
The protein structural unit of a virus capsid. Visible with an electron microscope. Consists of protomers. Includes hexons and pentons.
question
Carbohydrate
answer
A component of a virion. Associated with protein and/or lipids. Includes glycoproteins and glycolipids.
question
Carlos Finlay
answer
A Cuban who suggested in 1881 that mosquitoes could transmit yellow fever.
question
Case
answer
An individual who is suspected to have the disease in an outbreak.
question
Chamberland filter
answer
Invented by Edoard Chamberland in 1884. A filter used to sterilize water, using an unglazed ceramic powder. Effective in removing large bactiera, protozoa, and fungi from water, making it safe to drink. Cannot filter out viruses.
question
Chicken embryo
answer
Found in fertilized chicken eggs. Susceptible to many viruses, making them good hosts for culturing viruses.
question
Chicken sarcoma virus
answer
A disease discovered by Peyton Rouse in 1910. Symptoms include avian muscle cancer. The first virus found to cause cancer.
question
Chickenpox
answer
A childhood illness that used to be common, but is now preventable through a varicella vaccine. Caused by varicella zoser virus. Symptoms are itchy spots. It can cause dangerous complications in newborns, adults, and pregnant women. Before the development of the vaccine, it caused hospitalization in 11,000 Americans every year.
question
Cholera
answer
A disease. The person has diarrhea and can die from dehydration, but can be saved by forced rehydration. Every year, 100,000 people die from cholera. It is spread by contaminated water.
question
Circoviridae
answer
A family of viruses. Includes coconut foliar decay virus.
question
Circovirus
answer
A genus of isometric ssDNA viruses with a circular genome. 17 nm in diameter.
question
Classification
answer
Grouping of species according to shared physical properties. Includes Baltimore classification.
question
Closed structure
answer
Lenth of the nucleic acid dependson the structure. Isometric viruses have closed structure. There is a maxmum amount of nucleic acids which can fit in the capsid.
question
Closteroviridae
answer
A family of helical viruses. 12 x 2200 nm in size. Affects plant hosts.
question
Coconut foliar decay virus
answer
A DNA virus in the family Circoviridae. Has complete genome, 1.3 kb.
question
Coconut virus
answer
An ssDNA virus in the family Nanoviridae. Genome is 1.3 kb, with 3 open reading frames.
question
Colony
answer
A group of bacteria growing on an agar plate large enough that you can see it. Millions of bacterial cells can arise from one cell.
question
Communicable disease
answer
In ancient times, it was thought they were caused by divine intervention, imbalances of elements, miasmas, vapours, or spirits.
question
Complex
answer
A shape of virion. Has limit or no symmetry. A mixture of isometric and helical symmetry. Includes pox virus, rabies virus, T4 phage, pandornavirus, flowpox virus, and enterobacteria phage.
question
Conjunctiva
answer

Eyes

A portal of entry. Some herpesviruses and adenoviruses can infect through this point.

question
Constantin Levaditi
answer
In 1906 used chicken embryos to grow microorgnaisms. In 1909 showed that the poliomyelitis agent was a virus using tissue explants. Opened a small hole in the chicken egg to insert the virus. This method is used to make influenza vaccines.
question
Contagion
answer
A movie abotu a disease, based on a virus.
question
Core
answer
A component of the nucleocapsid. The DNA or RNA genome, and core nucleoproteins. The viral chromosome encodes all viral proteins, structural, and non-structural.
question
Coronaviridae
answer
A family of viruses. Includes beluga whale coronavirus and murine hepatitis JHM.
question
Coronavirus
answer
A genus of positive sense RNA viruses.
question
Coupled transcription
answer
Translation occurs at the same time as translation, with the ribosome attaching to mRNA while it is still being transcribed. Occurs in prokaryotes.
question
Coxsackievirus A 16
answer
A virus in the family Picornaviridae. Causes hand-foot-and-mouth disease.
question
Craig Venter
answer
In 2003, chemically synthesized ?X174 ssDNA genome in vitro from oligonucleotides. This was the first time DNA was synthesized.
question
Croup
answer
A childhood illness most common in children under the age of 5. Caused by parainfluenzavirus. Symptoms are a tight cough that sounds like a barking seal, caused by inflammation of the upper airways. If breathing becomes severely impaired, hospitalizaton may be required. Most children recover in about a week.
question
Cytopathology
answer

"Cell illness"

A criterion for demarcation of viruses into species. Cellular symptoms of a disease. Includes lysis, or occlusion bodies. Can be seen with microscopy.

question
Dead-end host
answer
A host which can contract a virus, but cannot transmit it. Horses are a dead-end virus for West Nile virus; horses can be affected by the virus, but a mosquito cannot acquire the virus from a horse.
question
Delta agent
answer
Has a subviral genome.
question
Demarcation criteria
answer
Things you can look at to determine taxonomy. Decided by the ICTV. Includes cytopathology, physiochemical, genome, proteome, and morphology.
question
Dmitri Ivanovsky
answer
In 1892, demonstrated that tobacco mosiac disease is caused by a filterable virus. In his experiments he filtered matter from an infected plant, and found that the fluid was still able to infect healthy plants. A healthy plant was infected with the fluid from another healthy plant as a control. Concluded that the disease is caused by something very small.
question
Direct release
answer
The method of release in naked viruses. The cell lysis, or there is apoptosis.
question
Disease
answer
A nomenclature system for viruses. Viruses are named for the disease they cause. Example: encephalitis virus, sarcoma virus.
question
DNA
answer
A compnent for DNA replication and transcription. Used as the template.
question
DNA binding protein
answer
A component for DNA replication.
question
DNA-dependent RNA polymerase (DrRp)
answer
Needed by DNA viruses for transcription of mRNA.
question
DNA helicase
answer
A component for DNA replication.
question
DNA polymerase
answer
A component for DNA replication.
question
DNA virus
answer
Includes ssDNA and dsDNA viruses, which can have linear or circular genomes. Genome size is 1.3 - 1200 kb. Needs DdRP to transcribe mRNA. Needs DNA polymerase (host or viral) to replicate the genome. The 5' cap is added to mRNA in the nucleus.
question
dNTP
answer
A type of molecule, a component of DNA. Includes dA, dG, dT, and dC.
question
Double stranded DNA (dsDNA)
answer
A type of DNA virus. Can have more variation in structure than ssDNA viruses. The dsDNA is transcribed into mRNA. The dsDNA is replicated into dsDNA for genome replication.
question
Double stranded RNA (dsRNA)
answer
A type of RNA virus. Genome is always segmented. The dsRNA is transcribed into mRNA. The dsRNA is transcribed into dsRNA for genome replication.
question
E. Volkin and L. Astrachan
answer
In 1956, indirectly discovered mRNA while studying T2 phage.
question
Early protein
answer
Proteins produced early in viral infection. Enzymes that interact with host defenses. May prevent apoptosis.
question
Ebola restin
answer
A virus that affects monkeys, and not people.
question
Ebola virus (EBOV)
answer
A simple, helical negative-sense ssRNA virus in the genus Ebolaviurs, family Filoviridae. Has a complete genome, 18.9 kb. The name of this virus comes from the Ebola River in the Congo, where it was first isolated. There are several species, including Zaire, Sudan, Tai Forest, Bundibugya, and Reston. The virion is long and filamentous, 90 nm in diameter and 1000 nm in length. It has an envelop with GP protein surface projections. Transcription begins at the 3' end, and can halt or continue at each point between reading frames, causing polypeptides near the 3' end to be most numerous than polypeptides near the 5' end. Protein components in the virion, in order of most to least translated are: NP, VP35, VP40, GP, sGP, VP30, VP24, and L. The virus can be detected in blood serum, even in people who are not sick. It can be transmitted by fruit bats, especially when eaten. It can last for 565 days in human semen.
question
Ebola virus outbreak
answer
Occured in Sierra Leone in 2013 - 2016. Caused 28,646 cases and 11,323 deaths. The virus peaked in November 2014, and the last case was in March 2016.
question
Ebolavirus
answer
A genus of viruses. Includes Ebola virus.
question
Eclipse phase
answer
The first phase of bacteriophage replication. There is no infectious virus produced. Virus is not detectable in this phase.
question
Edouard Chamberland
answer
Invented the Chamberland filter in 1884.
question
Egyptian priest
answer
Images of a priest were found, made in 1403 - 1365. Shows evidence of an injured leg from polio virus.
question
Emile Ouamouno
answer
The index case of Ebola; he contracted the disease in December 2013. He was a bat hunter, and may have contracted the disease from eating bats.
question
Emiliania huxleyi
answer
An organism affected by phycodnavirus.
question
Endemic
answer
When a disease is present in a local area.
question
Enterovirus
answer
A genus of RNA viruses.
question
Entomopoxvirus
answer
A genus of complex brick shaped viruses. 450 x 250 x 250 nm in size. Affects insect hosts.
question
Envelope
answer
Present in enveloped viruses. A lipid and protein membrane which surrounds the nucleocapsid. May have peplomers. Provides surface proteins for attachment to cell receptors, dictating host specificity. Does not provide very much protection; it can dry out, killing the virion. Dictates how the virus can enter a cell.
question
Envelope protein (E)
answer
A component of the Zika virus virion. A dimer.
question
Enveloped virus
answer
A virus which has an envelope. The nucleocapsid is usually flexible, to prevent shearing. Exit the host cell by budding. Transmission must be quick because the envelope can dry out. Includes herpesvirus and HIV.
question
Epidemic
answer
When a disease is present worldwide. HIV and influenza are epidemic.
question
Ernst Ruska and Max Knoll
answer
Invented the electron microscope in 1933. Ernst Ruska is the brother of Helmut Ruska, and won the Nobel Prize in 1986.
question
Escherichia coli
answer
Genome is 4,600 kb.
question
Eshmuna Code
answer
Written in 2300 BC. It mentions rabies.
question
Eukaryotes
answer
Cells have a nuclear membrane, endoplasmic reticulum, and Golgi body. There is nuclear processing including splicing, addition of 5' cap and 3' poly-A tails. mRNA has cytoplasmic translation and is monocistronic. Ribosomes are free as well as membrane-bound. No cell wall, plant and yeast cells excepted.
question
Eukaryotic initiation factor 4G (eIF4G)
answer
A cellular cap binding protein for the 5' cap of cellular mRNAs in eukaryotes. It is needed for ribosomes to recognize a cellular mRNA for translation. It is cleaved by viral proteases of poliovirus, causing cessation of translation of host mRNAs.
question
F. Bawden and N. Price
answer
In 1937, crystalized tobacco mosaic virus, and found that it contained protein and nucleic acid.
question
Family
answer

"-viridae"

A taxonomic level. There are 103 families of viruses.

question
Felix d'Herelle
answer
A Quebecois scientist who discovered plaques in Shigella lawns in 1915.
question
Fifth disease
answer

Slapped cheek disease

A childhood illness that first causes mild cold symptoms, then causes a bright red rash on the face, and may also appear on the torso, arms, or legs. Once rash appears the child is usually no longer contagious, and it lasts for seven to ten days. Caused by human paravirus B19. Very common; up to 60% of people have had it by age of 19.

question
Filoviridae
answer
A family of viruses. Includes Ebola virus.
question
Filovirus
answer
A genus of negative sense RNA viurses. Rod-shaped or helical. 80 x 14 ?m in size.
question
Filterable virus
answer
In the 1880s all infectious agents were called "viruses", at that time the term "filterable virus" was used for true viruses.
question
Flaviviridae
answer
A family of isometric viruses. 40 - 60 nm in size, with an envelope. Includes Zika and hepatitis C virus.
question
Flavivirus
answer
A genus of positive sense RNA viruses with a linear, non-segmented genome. Includes Zika and yellow fever.
question
Flu
answer
A disease caused by influenza virus. Symptoms are high fever, chills, body aches, extreme fatigue, nausea, and vomiting. Most children recover on their own, but the flue can lead to complications including pneumonia, especially in younger children. Annual flu vaccinations are recommended for children aged 6 months and older.
question
Fomite
answer
A non-living thing which can transmit a virus, such as blankets, clothes, or linens. Things which are not themselves, corrupt, but can foster the essential seeds of contagion, and cause infection.
question
Foot and mouth disease virus
answer
A disease of cattle and goats. Discovered by Fred Loeffler and Paul Frosch in 1898.
question
Forced rehydration
answer
Treatment of plenty of water with disolved sugar and salt. Used to treat hemorrhagic fever and cholera.
question
Fowl adenovirus 8
answer
A DNA virus in the family Adenoviridae. Has a complete genome, 45.1 kb.
question
Fowl avian leucosis
answer
A disease discovered by Wilhelm Ellerman and Olaf Bang in 1908. Symptoms include avian cancer.
question
Fowlpox
answer
A complex virus in the family Poxviridae. 330 x 280 x 200 nm in size. Affects fowl, causing a pox. Each pock is the site of a single viral infection.
question
Frank McFarlane Burnet
answer
In 1932, develoepd the chicken embryo as a host for some animal viruses, such as canarypoxvirus.
question
Fred Bawden and Norm Pirie
answer
In 1937 found that tobacco mosaic virus crystals contained 6% RNA.
question
Fred Loeffler and Paul Frosch
answer
Discovered foot and mouth disease in cattle in 1898.
question
Fred Twort
answer
Discovered glassey transformation of micrococci in 1915. Noticed that bacteria were being made to lyse.
question
Frederick Sanger
answer
In 1977, sequenced ?X174 ssDNA genome, which has 5,375 nucleotides.
question
Fusion
answer
A way that an enveloped virus may penetrate a cell. The envelope fuses with the plasma membrane, releasing the nucleocapsid into the cell. Includes measels virus, herpesvirus, and HIV.
question
Geminiviridae
answer
A family of viruses. Includes beet curly top virus.
question
Geminivirus
answer
A genus of ssDNA viruses with a circular genome. It looks like two parts stuck together.
question
Generalized eukaryotic virus replication
answer

Only a small fraction of virions produced are infectious.

1. Attachment. Viral glycoproteins bind to receptors on the host cell's membrane

2. Penetration. The viral core enters the cell

3. Uncoating. The viral genome is uncoated and the viral proteins degrade

4. Genome transcription. The viral genome is transcribed into mRNA

5. Translation. Enzymes are produced early on, then later on capsid proteins. The transcripts are translated into new capsid proteins and envelope glycoproteins

6. Genome replication. The viral genome is replicated

7. Transport of glycoproteins to cell membranes (enveloped viruses only). Glycoproteins are transported in vesicles to the host plasma membrane

8. Virus assembly. New virions assemble from replicated genome and capsid proteins. Genome, capsid, proteins, and envelope all assemble

9. Release from the cell.

question
Genome
answer
A criterion for demarcation of viruses into genera and families. Whether the genome is DNA or RNA, positive, negative, or double stranded. Often the first demarcation criteria to be checked.
question
Genome replication
answer
A component of biosynthesis. Replication of the viral genome.
question
Genus
answer

"-virus"

A taxonomic level. There are 455 genera of viruses.

question
Geography
answer
A nomenclature system for viruses. VIruses are named after places. Example: Powassan virus.
question
Girolamo Fracastoro
answer
An Italian scientist from 1546. Said that epidemic diseases were due to infection with transferable minute bodies. Defined fomites.
question
Glassey transformation of micrococci
answer
A bacteriophage discovered by Fred Twort.
question
Glycolipid
answer
A component of a virion. Found in the envelope.
question
Glycoprotein
answer

"Sugar protein"

A component of a virion. Found in the envelope or the capsid.

question
Glycoprotein (GP)
answer
An open reading frame in the Ebola virus genome. Encodes a major envelope homotrimer protein, the fourth most numerous polypeptide. A surface protein that latches onto the cell. It is sensed by the immune system, which produces antibodies to cover the glycoprotein. Assists in budding of nucleocapsids from cells.
question
Glycosylation
answer
A post-translational protein modification. Carbohydrates are added to polypeptide. Only certain amino acids can be glycosylated.
question
Golgi protease
answer
A peptide that cleaves the Zika virus polyprotein.
question
Goose hepadnavirus
answer
A dsDNA virus with 3.0 kb, with 4 open reading frames.
question
Grapevine stem pitting disease virus
answer
Research is being done on this virus by Dr. Baozhong Meng at the University of Guelph.
question
Great flue pandemic
answer
An outbreak of Spanish flu that occurred in 1918, causing 20 - 70 million deaths, mostly in India.
question
Greek
answer
A nomenclature system for viruses. Viruses are named with Greek words. Example: rhabdovirus (rod).
question
Guy Carleton
answer
Commanded the British army in the American Revolutionary War.
question
H.H. McKinney
answer
In 1926, isolated variants of tobacco mosaic viurs based on lesion morphology.
question
Haemaglutinin (HA)
answer
A surface protein of influenza virus. Trimeric. Has 16 subtypes. Causes red blood cells to stick together.
question
Hand-foot-and-mouth disease
answer
A childhood illness that causes fever and blisters on the inside of the mouth, palms of the hands, buttocks, and soles of the feet. Caused by coxsackievirus A 16. Tends to spread among children during summer and early fall. Most children recover in a week to ten days.
question
Hector
answer
A Trojan protecting Helen from being returned to the Greek King Menelaus. He was described as being very mad, and having foam coming from hist mouth, suggesting that he had rabies! He might have spread the rabies virus to Achilles.
question
Heinz Fraenkel-Conrat and Beatrice Singer
answer
In 1957, did a classic experiment that proved that RNA was the genetic material in tobacco mosaic virus. At this point in time it was known that DNA was the genetic material in living organisms. Dissociated two different mutants of the virus into protein and RNA, then re-associated the protein with the opposite RNA. Plants infected with tehse new viral agents produced the virus phenotypes of the RNA donor.
question
Heinz Fraenkel-Conrat and Robley Williams
answer
In 1952 dissociated tobacco mosiac virus agent into protein and RNA fractions, and found that they occurred in a 200:1 ratio. They could re-associated protein and RNA into infectious tobacco mosaic agent.
question
HeLa cells
answer
An immortalized cell culture collected from the cervical cancer of Henrietta Lacks in 1951. These cells are still alive.
question
Helical
answer

Rod-shaped

A shape of virion. Has radial symmetry. Capsid proteins wrap around the core in a helical pattern to form a rod. May only use one protomer. Includes tobacco mosaic virus, infuenza virus, and Ebola virus. Have open structure.

question
Helicase
answer
A component for transcription.
question
Helmut Ruska
answer
Observed tobacco mosaic virus using an electron microscope in 1939. The brother of Ernst Ruska.
question
Hemorrhagic fever
answer
Caused by Ebola virus. Blood oozes from pores. Vomiting and diarrhea, and the person can die from dehydration, but they can be saved by forced rehydration.
question
Henle/Koch's postulates
answer

Proposed by Robert Koch. Prove that an agent causes a specific disease.

1. Every diseased organism has the agent, and every healthy organism lacks the agent

2. The agent can be grown in a "pure culture"

3. Infection of a healthy organism with the pure culture of the agent should cause the same disease

4. The diseased organism shows evidence of the agent, and the agent can be re-isolated and cultivated and shown to be the same.

question
Henry Bouquet
answer
A colonel who in his correspondence with Jeffrey Amherst, said he would try to inoculate Native Americans with smallpox using blankets.
question
Hepadnavirus
answer
A genus of dsDNA retroviruses with a circular genome. Some parts of the genome are double-stranded, and some parts are single-stranded. The DNA enters the nucleus, is repaired to become fully ddDNA, then it is transcribed into +RNA, then into -ssDNA, then transcribed into dsDNA that is transcribed into mRNA. The mRNA is then exported from the nucleus for translation. Pleomorphic; some are long, and some are spherical.
question
Hepatitis
answer
A disease of the liver. Can be caused by many viruses.
question
Hepatitis A virus
answer
A virus in the family Picornaviridae.
question
Hepatitis B virus
answer
A DNA virus.
question
Hepatitis C virus
answer
An RNA virus in the family Flaviviridae. Has a complete genome, 9.4 kb.
question
Herpesviridae
answer
A family of isometric viruses. 100 - 110 nm in size. Includes varicella zoser virus and human herpesvirus 2.
question
Hepevirus
answer
A genus of positive sense RNA viruses. Isometric, T = 16.
question
Herpesvirus
answer
A genus of dsDNA viruses. 200 nm in diameter. Causes a latent infection, activated by stress hormones; can cause cold sores. Once a person contracts it, they have it for life. A latent virus, stimulated to reproduce by stress hormones. Isometric, with 12 pentons composed of the same protomer as the 150 hexons. Only one gene is needed. Has larger capsomers than adenovirus, and is larger than adenovirus, despite having a smaller T value. Has an envelope with a tegument. Buds through the endoplasmic reticulum or Golgi body when released. During translation there is a scaffold that disintegrates once capsids are formed.
question
Hexon
answer
A capsomere of any shape found within the 20 triangular faces of an isometric virion. Generally six-sided, and consisting of 6 protomers. If you have only hexons, they make a flat surface.
question
Host
answer
A nomenclature system for viruses. Viruses are named for their hosts. Example: tobacco mosaic virus, human herpesvirus.
question
Host range
answer
A phenotype of a virus. A criterion for demarcation of viruses into species. The range of hosts that a virus can infect. The host species, tissue, and cells affected. In tobacco mosaic virus, some mutants can also infect tomato.
question
Human
answer
Genome is 3.038 billion bp, with 25,000 open reading frames. Humans are susceptible to about 100 viral diseases.
question
Human enterovirus-D68
answer
A virus related to polio. Children are susceptible to it, because they don't have immunity. Symptoms can include paralysis and a runny nose. There was an outbreak in BC in September 2016, with 8 confirmed cases.
question
Human herpesvirus 2 (HSV2)
answer
A DNA virus in the family Herpesviridae. Has a complete genome, 154.7 kb.
question
Human immunodeficiency virus (HIV)
answer
A complex RNA virus in the family Retroviridae. 110 nm in diameter. Has a complete genome, 9.2 kb. Transmitted sexually; there must be tears in sexual organs for transmission. Capsid consists of two halves of an icosahedron, separated by a tubular layer of hexons. Has an envelope.
question
Human influenza virus
answer
During attachment, it recognizes ?2, 6 linkage between sialic acid and galactose.
question
Human papillomavirus (HPV)
answer
A virus that is transmitted sexually. The cause of most cervical cancer. There are 9 differen types.
question
Human papilloma virus type 52
answer
A DNA virus in the family Papoviridae. Has a complete genome, 7.9 kb. Causes cervical cancer.
question
Human paravirus B19
answer
A virus in the family Parvoviridae. Causes fifth disease.
question
Human rhinovirus 16
answer
An RNA virus in the family Picornaviridae. Has a complete genome, 7.1 kb.
question
Icosahedron
answer
A polyhedron with 12 pentagonal apexes, 20 triangular faces, and 30 edges. Has 5:3:2-fold axes of symmetry. Similar to a geodesic dome, or a soccer ball. Triangular faces may each contain one or more hexagons, depending on the size of the icosahedron and the triangulation number.
question
Immortalized cell culture
answer

Continuous culure

A kind of tissue culture. Cells are grown on fresh medium. Not all cells are capable of this. Includes HeLa cells.

question
Inclusion body
answer
Virogenic stroma areas of virus assembly. Clusters of capsids where a virus is replicating in a cell. Visible by light microscopy.
question
Index case
answer
The first human individual confirmed to have the disease in an outbreak.
question
Infectious pancreatic necrosis virus (IPNV)
answer
A virus that affects fish.
question
Influenza virus
answer
An RNA virus is the famliy Orthomyxociridae. Has an ssRNA segmented genome with 8 segments, encoding 8 nucleocapsids. May be transmitted by ducks. Symptoms may be similar to the cold or to the flu. Has a membrane. Can be pleomorphic. Virion has two surface proteins: haemaglutinin and neuraminidase. The receptor for virus attachment is sialic acid. Human and avian influenza viruses can both affect pigs; there can be recombination of viral genes in pig cells infected by both. Buds through the plasma membrane when released. The 5' cap of the genome is stolen from cellular mRNAs, and the poly-A tail is encoded.
question
Influenza H5N1
answer
A virus that affects ducks. There was an outbreak recently in St. Catherine's.
question
Insect polydnavirus
answer
A dsDNA virus with a circular, polydisperse genome.
question
Internal ribosome entry site (IRES)
answer
A sequence of poliovirus mRNA that acts like a 5' cap, allowing the ribosome to recognize it and translate mRNA.
question
International Committee on Nomenclature of Viruses (ICNV)
answer

1966 - 1973

First meeting was at the Ninth International Microbiology Congress in Moscow. Has accepted rules for viral classification.

question
International Committee on Taxonomy of Viruses (ICTV)
answer

1973 - present

Tries to classify all viruses. Responsible for updated reports of the ICTV. The most recent is the 9th report, 2011. Define criteria for demarcation of viruses.

question
Iridoviridae
answer
A gamily of isometric viruses. 170 nm in size.
question
Iridovirus
answer
A genus of large dsDNA viruses with a linear, circularly permuted genome. Forms iridescence when crystalized. Insect larvae infected have iridescence.
question
Isometric
answer

Spherical

A shape of a virion. Has icosahedral symmetry. Allows for limited viral genome; the capsid is composed of one or two polypeptides. All have 12 penton capsomers, and hexon capsomers within the 20 triangular faces, number indicating the triangulation value of the virus. Have closed structure. Includes rhinovirus, poliovirus, flavivirus, herpesvirus, Zika virus, and adenovirus.

question
James Hillier, Albert Prebus, and Eli Franklin Burton
answer
Built the first practical electron microscope prototype in the USA in 1938.
question
James Kates
answer
In 1970, discovered polyadenylation of mRNAs in vaccinia virus.
question
Jeffrey Amherst
answer
A British general who in 1763 suggested germ warfare by distributing smallpox-contaminated blankets to the Native American allies of the French. Wrote a letter to Colonel Henry Bouquet discussing it.
question
Jesse Lazear
answer

1866 - 1900

Worked on mosquito transmission of malaria. Worked on rearing and infecting mosquitoes. Worked with Walter Reed in yellow fever research, and was interested in testing Dr. Finlay's theory of mosquito transmission. Could not satisfy Koch's postulates using the suspected bacteria, Bacillus icteroides. Began experiments using infected mosquitoes, allowing them to infect volunteers at different days post infection. Only mosquitoes which had been infected for 12 days or more could transmit the disease. He died from yellow fever himself at age 34.

question
John Enders
answer
Grew poliovirus in African green monkey kidney cells. Won a Nobel Prize in 1954.
question
Justin Trudeau
answer
Raised money for HIV, malaria, and tuberculosis research, to find new drugs and treatments.
question
KDEL
answer
A signal which retains proteins in the endoplasmic reticulum.
question
Kilbase (kb)
answer
1000 base pairs. About the size of one gene.
question
L.K. Miller
answer
In 1994, discovered the first inhibitor of apoptosis (IAP) in P38 baculoviruses.
question
lamB
answer
The bacterial binding protein for maltose, and important energy source. The receptor for lambda phage. Bacteria which lack this receptor are resistant to lamba phage.
question
Lambda phage
answer
The first virus discovered to attack bacteria. Its receptor is lamB. Causes lysis of bacterial cells.
question
Late protein
answer
Proteins produced late in a viral infection. Proteins for virus structure and release, produced in greater amounts than early proteins.
question
Latent phase
answer
The third phase of bacteriophage replication. The period prior to extracellular virus release.
question
Latin
answer
A nomenclature system for viruses. Viruses are named with Latin words. Example: baculovirus (stick).
question
Left-handed helix
answer
No screws for carpentry have a left-handed helix, but if they did, if you turned it clockwise, the screw would come out of the wood.
question
Ligase
answer
A component for DNA replication. Puts together Okazaki fragments.
question
Limiting dilutions
answer
Can be used to clone a virus for a pure culture. A solution containing a virus is diluted until there is one virion.
question
Lipid
answer
A type of molecule. Amphipathic with polar and apolar regions. Forms the envelope of enveloped viruses. Naked viruses have no lipids in their virion.
question
Lipid bilayer
answer
A macromolecule of lipid proteins. Has hydrophobic interactions.
question
Listeria monocytogenes
answer
A disease that contaminates deli meats, cheese, and mushrooms.
question
LISTEX
answer
A bacteriophage product that is effective against Listeria monocytogenes.
question
Lytic infection
answer
After uncoating, the virus multiplies and lysis occurs, releasing new viruses. Viruses produced infect adjacent cells, and move through tissues.
question
Malaria
answer
A virus transmitted by mosquitoes.
question
Marcus Terentius Varro
answer
A Roman scholar/philosopher from 100BC. The first microbiologist/epidemiologist/virologist. Suggested that people avoid swamps, which he said bred minute creatures, which could not be seen but which floated in the air, and entered via the mouth and nose to cause diseases. Actually it was mosquitoes breeding in swamps that were spreading disease.
question
Martinus Beijerinck
answer
A Dutch scientist who in 1898 carried on Dmitri Ivanovsky's observations, and saw that the filterable agent causing tobacco mosaic virus could not be seen by the highest resolution available at the time, that it spread systemically throughout the plant, it could not be grown in plant sap in a test tube, and it could be continuously passed from infected plants to healthy plants. It had biological properties in terms of its replication. Could not satisfy the Henle/Koch's postulates. He called it Contagium vivum fluidum: "living contagious fluid".
question
Mary and Hugh Maitland
answer
In 1911, used medium for growing tissue cultures. Used Tyrode's solution, blood serum, and minced tissue. Grew vaccinia virus in chicken kidney cells. Had problems with contamination; competition between virus and bacterial or fungal contaminations.
question
Matrix
answer
The layer between the nucleocapsid and envelope. Includes tegument.
question
Matrix protein VP40
answer
An open reading frame in the Ebola virus genome. Encodes viral protein 40 kDa, the third most numerous polypeptide. A major matrix protein between the nucleocapsid and envelope. Assists in budding of the nucleocapsid from cells.
question
Maturation
answer
The seventh sequelae of virus replication. There is modification of the virus into its infectious form. Most viruses mature right away, but some need time, including picornavirus and poliovirus; they do not cleave their proteins completely in the cell.
question
Maturation phase (bacteriophage)
answer
The second phase of bacteriophage replication. A few new viruses are assembled inside the cell.
question
Measles
answer
A childhood illness that is preventable with the MMR vaccine. Infection starts with a fever, runny nose, and cough. As symptoms fade, full-body rash appears. Most children recover in two weeks, but some can develop pneumonia or other problems. Cause by viruses in the family Paramyxoviridae. Outbreaks have been reported among unvaccinated children, and there was an oubreak recently in Ottawa. Virion is enveloped, with helical symmetry. No longer endemic to the Americas, due to vaccines. An RNA virus.
question
Measlevirus
answer
A genus of RNA viruses.
question
Megavirus
answer
A genus of viruses discovered in 2011. Isometric shape, 440 nm in diameter. Affects acanthamoeba hosts. Genome is 1,250 kb with 1,120 genes.
question
Megavirus salinus
answer
A dsDNA virus with 2,472.9 kb, with 2,541 open reading frames. Affects amoeba hosts.
question
Membrane protein (M)
answer
A component of the Zika virus virion.
question
Mimiviridae
answer
A family of isometric viruses.
question
Mimivirus
answer
A genus of dsDNA viruses. Asymmetrical shape. 400 nm in diameter, with 100 nm filaments. Affects amoeba hosts. Genome is 1,181.4 kb, with 911 open reading frames.
question
Minor matrix protein VP24
answer
An open reading frame in the Ebola virus genome. Encodes viral protein 24 kDa, the second least numerous polypeptide.
question
Mitovirus 6-Ld
answer
A positive sense ssRNA virus in the family Narnaviridae. Genome is 2.3 kb. Affects mitochondria.
question
MMR vaccine
answer

Mumps, Measles, Rubella vaccine

Prevents mumps, measles, and rubella. It is usually given to children at the age of 12 months.

question
Mode of replication
answer
A criterion for demarcation of viruses into genera and families.
question
Mononegavirales
answer
An order of viruses with a single, negative-sense RNA genome. Includes Ebola virus.
question
Morphology
answer
A criterion for demarcation of viruses into genera and families. The shape and size of virion, and if it has an envelope. Visualized with electron microscopy and negative staining.
question
Mouth
answer

Oral

A portal of entry. Human herpes virus 1 and enterovirus D-68 can infect through this point.

question
mRNA
answer
A component for translation. Used as a template.
question
Mumps
answer
A childhood illness that was common before the MMR vaccine was developed. Often causes no symptoms, but when it does it causes swollen glands between the jaw, creating the appearance of "chipmunk cheeks". Caused by viruses in the family Paramyxoviridae. Despite high vaccination rates, recent outbreaks have infected thousands of people in the USA.
question
Murine hepatitis JHM
answer
An RNA virus in the family Coronaviridae. Has a complete genome, 31.4 kb.
question
Myoviridae
answer
A family of viruses. Includes T4 phage.
question
Naked virus
answer
A virus which lacks an envelope. The capsid attaches to cell receptors, dictating host specificity. The nucleocapsid is rigid or flexible. Incldues poliovirus.
question
Nanoviridae
answer
A family of viruses. Incldues coconut virus.
question
Narnaviridae
answer
A family of viruses. Includes mitovirus 6-Ld.
question
Nature of protein
answer
A criterion for demarcation of viruses into genera and families. The size of proteins and enzymes.
question
Negative sense RNA (-RNA)
answer

Anti-sense-like

Written 3' to 5'. The genome is complementary to mRNA, and cannot be translated. All negative sense viruses encode for a polymerase for RNA. The -RNA is transcribed into mRNA. The -RNA is transcribed into +RNA, then into -RNA for genome replication.

question
Negative staining
answer
Adding stain to areas between objects you want to see. The canyon between hexons of a virus might be stained.
question
Negri bodies
answer
Inclusion bodies of rabies virus.
question
Neuraminidase (NA)
answer
A surface protein of influenza virus. Tetrameric. Has 9 subtypes.
question
Nodavirus
answer
A genus of positive sense RNA viruses.
question
Nomenclature
answer
Assignment of names. Includes binomial nomenclature, and naming a virus by a host or a disease.
question
Non-segmented ssRNA
answer
An ssRNA virus with the RNA in one piece.
question
Non-structural protein
answer
Intracellular viral proteins that help the virus replicate.
question
Non-structural protein (NS 1 - 5)
answer
Components of the Zika virus virion.
question
NS3 protease
answer
A peptide that cleaves the Zika virus polyprotein. It frees up the NS3 protein. This protein is carried in the virion.
question
Nuclear export signal (NES)
answer
Tags which localize proteins out of the nucleus. Discovered by U. Fisher et al in 1995. Rich in leucine. Some virus proteins have an NES.
question
Nuclear localization signal (NLS)
answer
Tags which localize proteins to the nucleus. Discovered by A.E. Smith in 1984. In SV40 the NLS tag is PKKKRKV. Many virus proteins have an NLS, including T antigen.
question
Nucleic acid
answer
A macromolecule made of dNTP (DNA) or rNTP (RNA) polymers bound by phosphodiester bonds. A component of a virion, forming the genome.
question
Nucleocapsid
answer
A component of a virion. A protein and nucleic acid structure. Includes the core and capsid.
question
Nucleoprotein (NP)
answer
An open reading frame in the Ebola virus genome. Encodes a major protein coating the RNA genome. It is the most-produced protein of Ebola virus; more of it is needed than any other component.
question
Occlusion body
answer
Nucleocapsids assembled in a virioplasm. Consists of viral RNA and proteins. Can be seen with microscopy.
question
Oncolytics
answer
Some viruses can be used to kill cancer cells, or a gene can be introduced to cure a genetic disease.
question
Open reading frame (ORF)
answer
A component for translation. Must have an AUG codon.
question
Open structure
answer
Structure depends on the length of nucleic acid. If you add more nucleic acid, it gets larger. Helical viruses have open structure.
question
Order
answer
A taxonomic level. Not all viruses have an order. There are 7 orders of viruses.
question
Orthomyxoviridae
answer
A family of viruses. Includes influenza virus.
question
Orthomyxovirus
answer
A genus of negative sense RNA viruses with a linear, segmented genome.
question
Outbreak
answer
A movie based on the Ebola virus.
question
P53
answer
An important protein in humans that prevents tumour growth, and is needed for normal replication. It recognizes when cells are replicating uncontrollably, and induces apoptosis. It is an enhancer of gene transcription. T-antigen interferes with P53.
question
Palisade layer
answer
A fence-like layer that surrounds the core of a nucleocapsid.
question
Panama Canal
answer
During its construction, mosquitoes had to be controlled to prevent illness and deaths from yellow fever and malaria.
question
Pandoravirus
answer
A genus of viruses discovered in ice in 2003, and discovered to be a virus in 2013. Shaped like a Greek jar, 1 ?m in size. Affects amoeba hosts. Genome has approximately 2,500 genes.
question
Papillomavirus
answer
A genus of dsDNA viruses. Causes cancer.
question
Papovaviridae
answer
A family of isometric viruses. 18 - 26 nm in size. Includes human papillomavirus type 52.
question
Parainfluenzavirus
answer
A genus of viruses in the family Paramyxoviridae. Causes croup.
question
Paramyxoviridae
answer
A family of viurses. Includes parainfluenzavirus, respiratory syncytial virus, and viruses which cause measles and mumps.
question
Paramyxovirus
answer
A genus of negative sense RNA viruses with a linear, non-segmented genome.
question
Parvoviridae
answer
A family of viruses. Includes human paravirus B19.
question
Parvovirus
answer

"Small"

A genus of ssDNA viruses with a linear genome. 22 nm in diameter. Affects mammal and insect hosts. Isometric, consisting of 22 pentons. There are no hexons. Only the penton protein gene is required. A small virus.

question
Pathogenicity
answer

Pathology

A criterion for demarcation of viruses into species. What diseases the virus causes. Includes encephalitis, hepatits.

question
Penetration
answer
The second sequelae of animal virus infection and virus replication. Common to all viruses. The virus penetrates into the cell. There is fusion or receptor-mediated endocytosis. With naked viruses, there may be direct penetration through the cell membrane (poliovirus, SV40).
question
Penton
answer
A five-sided capsomere. Located at the 12 apices of an isometric virion. Generally consists of 5 protomers. Important, because they give curvature to the surface of the virion.
question
Peplomer
answer
Glycoprotein spikes on the envelope of a virion.
question
Permissive
answer
A cell that allows a virus to replicate inside it. Necessary for the virus to replicate.
question
Persistent infection
answer
After uncoating, the infected cell has a persistent infection and slow virus release. New viruses are produced and released one at a time, without killing the cell.
question
Peyton Rouse
answer
Discovered chicken sarcoma in 1910.
question
Phage
answer
An ssDNA virus in the family Inoviridae. Genome is 9.0 kb, with 9 open reading frames.
question
Pharaoh Ramses V
answer
Lived in Egypt in 1157 BC. His mummy has pock marks on his face and neck, which may have been caused by smallpox. A sample from the pocks proved this.
question
Phillip Allen Sharp and Richar J. Roberts
answer
In 1977, discovered splicing of eukaryotic mRNA in adenovirus.
question
Phosphorylation
answer
A post-translational protein modification. Phosphates are added to the polypeptide. Often a signal to activate or inactivate a process.
question
Phycodnaviridae
answer
A family of isometric viruses. 130 - 200 nm in size.
question
Phycodnavirus
answer
A genus of dsDNA viruses. Genome has 407.3 kb, with 472 open reading frames. Affects Emiliana huxleyi hosts. Isometric, T = 1179.
question
Physiochemical/antigenic properties
answer
A criterion for demarcation of viruses into species. The serotype of a virus.
question
Picornaviridae
answer
A family of isometric viruses. 22 - 30 nm in size. Includes hepatitis A virus, coxsackievirus A 16, and human rhinovirus 16.
question
Picornavirus
answer
A genus of positive sense RNA viruses with a linear, non-segmented genome.
question
Pitch (P)
answer

The pitch between each turn of the helix

P = ? x p

question
Pneumonia
answer
Caused by RSV, or complications of the flu.
question
Plague
answer
Caused by Yersinia pestis.
question
Plant viruses
answer
Research is cheap, and they are easy to grow and handle. Cause many plant diseases.
question
Plaque
answer
An area on a lawn of cells where a virus has infected the cells, causing a clearing of cells. Analogous to a botanical colony. Not all viruses form plaques. Bacterial or animal cells may be used.
question
Plaque assay
answer
Similar to a bacterial colony on agar. Permissive cells, such as HeLa cells are diluted to a monolayer, and are often dyed.
question
Plaque morphology
answer
A phenotype of a virus. The size and/or appearance of a virus plaque.
question
Plectovirus
answer
A genus of rod-shaped or helical viruses. 14 x 71 nm in size.
question
Pleomorphic
answer
Changing shape.
question
Poliovirus
answer
A genus of viruses. The genome is 7,000 bp. A simple virus with 4 capsid proteins. Attaches to receptor pvr, and releases hydrophobic VPI arms into the plasma membrane. Has either membrane invagination into an endosome or penetrates into the plasma membrane as a free virus. The +RNA has a VPg attached to its 5' end, which is removed in the nucleus and then the +RNA is translated into mRNA. The mRNA is translated into a polyprotein which is cleaved into equal amounts of VP4, 3, 2, and 1, as well as protease RdRp, RNA polymerase, and VPg. Extra unused proteins are wasted. For genome replication, the +RNA is translated into -RNA and then into +RNA, amplifying the amount. It is released from the cell by lysis, and has a maturation phase in which VP0 cleaves into VP2 and VP4. RdRp causes translation of cellular mRNA to halt by cleaving eIF4G. It affects only certain cells of the human body. There is an effective vaccine for it.
question
Poliovirus receptor (pvr)
answer

CD 155

The receptor that poliovirus attaches to.

question
Polyadenylation
answer
Increases the life of an mNRA. The poly-A til is chewed up.
question
Polydnavirus
answer

"Poly-DNA"

A genus of viruses with more than one strand of DNA.

question
Polymerase (L)
answer
An openin reading frame in the Ebola virus genome. Encodes large protein, the least numerous polypeptide; only one is needed for the Ebola virion. All RNA viruses have an L protein. The polypeptide is cleaved into smaller pieces. A major component of RNA polymerase (RdRp).
question
Polymerase co-factor VP35
answer
An open reading frame in the Ebola virus genome. Encodes viral protein 35 kDa, the second most numerous polypeptide.
question
Polyomavirus
answer
A genus of dsDNA viruses with a circular genome. Causes liver cancer. Isometric capsid, consisting only of pentons. Pentons make up the apices as well as triangular faces, with three pentons per triangular face. Only one protomer is needed. Has a small genome, but produces T-antigen.
question
Polypeptide
answer
A macromolecule made of amino acid polymers bound by peptide bonds. Translated from one mRNA strand.
question
Polyprotein
answer
A large polypeptide produced by viruses with one reading frame. It is cleaved into smaller polypeptides to form the structural and non-structural proteins of the virus.
question
Polysaccharide
answer
A macromolecule made of sugar polymers bound by glycosidic bonds. A carbohydrate.
question
Portals of entry
answer
Points in the human body through which a virus can infect. Includes mouth, respiratory tract, alimentary tract, urogenital tract, anus, skin, capillary, arthropod, scratch or injury, and conjunctiva.
question
Positive sense RNA (+RNA)
answer

Sense-like

Written 5' to 3'. The ssRNA genome is in the same sense as mRNA. The +RNA is transcribed into -RNA then into mRNA; this amplifies the amount of mRNA synthesized. The +RNA is transcribed into -RNA then into +RNA for genome replication.

question
Positive staining
answer
Adding stain to objects you want to see
question
Post-translational modification
answer
Modification of viral polypeptides in the endoplasmic reticulum and Golgi body. Can include cleavage of a polyprotein, removal of signal sequences, and protein modifications such as glycosylation, phosphorylation, acylation, and sulfation. Splicing always occurs in the nucleus.
question
Powassan virus
answer
An enterovirus first discovered in Powassan, Ontario.
question
Poxviridae
answer
A family of viruses. Includes vaccinia and fowlpox.
question
Poxvirus
answer
A genus of dsDNA viruses with a linear genome with covalently closed ends. One of the larger viruses. Infects orally, but signs of the virus ar visualized on the skin surface.
question
Primary culture
answer
A kind of tissue culture. Comes directly from tissues. The first cells to form the tissue.
question
Prokaryotes
answer
Cells that have no nuclear membrane, endoplasmic reticulum, or Golgi body. Coupled transcription and translation in the cytoplasm. The mRNA is polycistronic, and ribosomes are free. There is often a cell wall.
question
Protease
answer
Breaks up a polyprotein.
question
Protein
answer
A macromolecule made of one or more polypeptides. A component of a virion, including structural and non-structural proteins.
question
Proteome
answer
A criterion for demarcation of viruses into genera and families. Analyzed by mass spectrometry. You can test for RNA polymerase enzyme to determine if a virus is negative-sense RNA.
question
Protomer
answer
A polypeptide subunit of a capsomer.
question
Pseudo virus
answer
A polypeptide subunit of a capsomer.
question
Quarantine and burial practices
answer
Very important for the control of spread of disease during an outbreak.
question
Rabbit fever
answer
Caused by Francisella tularensis.
question
Rabies virus
answer
A helical virus in the family Rhabdoviridae. 45 x 180 nm in size. Transmitted by animals.
question
Receptor-mediated endocytosis
answer
The most common way a virus penetrates a cell. The virus is ingested by the cell into an endosome or caveosome. The endosome is acidified, causing release of the nucleocapsid or viral genome from the endosome into the cytoplasm, by various mechanisms.
question
Release
answer
The sixth sequelae of virus replication. Structural proteins and the viral genome self-assemble into nucleocapsids, and there is viral release by direct release by lysis, budding, or by remaining cell-associated.
question
Renato Dulbecco et al
answer
Worked in poliovirus plaque assays and tumour virology of Rous sarcoma virus. Won a Nobel Prize in 1975.
question
Reoviridae
answer
A family of viruses. Includes rotavirus.
question
Reovirus
answer
A genome of dsRNA viruses with a linear, segmented genome.
question
Replication
answer
A nuclear molecular process. Copying of nucleic acid to form complementary strands of DNA or RNA. Uses DNA or RNA polymerase, replicase.
question
Respiratory syncytial virus (RSV)
answer

Bronchiolitis and pneumonia

A childhood illness that is the top cause of bronchiolitis and pneumonia in infants in the USA. Symptoms are flu-like at first; fever, runny nose, and cough. Up to 40% of children with RSV infection will develop wheezing, and up to 2% will require hospitalization. Symptoms tend to be milder in older children and in adults. Caused by a virus in the family Paramyxoviridae.

question
Respiratory tract
answer
A portal of entry. The virus is breathed into the body. Influenza virus and rhinovirus can infect through this point.
question
Restriction and modification
answer
A system of bacterial host resistance to foreign DNA. Foreign DNA is recognized by its complementariness and it is prevented from replicated.
question
Retroviridae
answer
A family of viruses. Includes HIV.
question
Retrovirus
answer
A genus of positive sense RNA retroviruses with a linear, diploid genome. A complex virus, cone shaped, 80 nm in diameter. The +RNA is transcribed into -ssDNA in the cytoplasm, then transcribed into dsDNA which enters the nucleus and is transcribed into mRNA. The +RNA is transcribed into dsDNA then into +RNA for genome replication. The only viruses with a diploid genome; there are two copies of +RNA in the virion.
question
Rhabdoviridae
answer
A family of viruses. Incldues rabies virus.
question
Rhabdovirus
answer
A genus of negative sense RNA viruses with a linear, non-segmented genome.
question
Rhinovirus
answer

"Nose"

A genus of viruses. Causes the common cold.

question
Ribosome
answer
Similar in size to a virus. Viruses do not code for ribosomes, and must use host ribosomes. A component for translation. Large and small components are both needed.
question
Richard Montgomery
answer
Commanded George Washington's American army in the American Revolutionary war with Benedict Arnold. This army outnumbered the British army, but still lost.
question
Rideau Canal
answer
An icosahedron-shaped structure was partially submerged in the ice.
question
Right-handed helix
answer
All screws for carpentry are right-handed. If you turn it clockwise, the screw will go into the wood.
question
RNA-dependent RNA polymerase (RdRp)
answer
A viral protein needed by RNA viruses for transcription of mRNA. Some viruses carry an RNA polymerase in their virion. Large protein (L) is a major component. It "stutters" as it transcribes; goes back and forth over stretches of adenine, coming off or staying on at certain points. In poliovirus it acts as a protease, cleaving the polyprotein into its parts, as well as cleaving and inactivating eIF4G, halting translation of cellular mRNA.
question
RNA virus
answer
Includes ssRNA and dsRNA. There is a limit to the size of the genome; 30.0 kb is about the maximum. Most have filamentous morphology due to shearing forces. Need RdRP to trasncribe mRNA.
question
RNase H
answer
A component for DNA replication. Makes RNA primers.
question
rNTP
answer
A type of molecule. Includes A, G, U, and C. Components of RNA.
question
Robert Koch
answer
Developed germ theory in 1874. Developed staining and microscopy to visualize microorganisms in diseased animals. Discovered anthrax endospores. Helped propose the Henle/Koch's postulates.
question
Rotavirus
answer
A genus of viruses in the family Reoviridae. Causes severe diarrhea.
question
Rubella
answer

German measles

A mild virus that usually causes no serious probelms, and is preventable with the MMR vaccine. Can harm the fetus if a pregnant women becomes infected. Symptoms are a low fever and rash that spreads from the face to the rest of the body. Caused by a virus in the family Togaviridae.

question
SARS
answer
A virus. Genome is 29.8 kb. It was first sequenced by scientists from University of British Columbia. There was an outbreak in Canada.
question
Satellite
answer
Has a subviral genome.
question
Scratch or injury
answer
Penetration of the skin to underlying tissues and circulatory system. A portal of entry. The route of cutaneous vaccination, including for smallpox. Rabies virus, Ebola virus, and HIV can infect through this point.
question
Segmented ssRNA
answer
An RNA virus with the RNA in more than one piece. Each piece encodes about one gene.
question
Sequelae of animal virus infection
answer
Events that occur during an animal virus infection. Attachment, penetration, and uncoating, followed by either lytic infection, persistent infection, cell transformation, or virus latency.
question
Serotype
answer
A group of viruses which react to the same antibodies.
question
Severe diarrhea
answer
A childhood illness that was the top cause of diarrhea-related deaths in young children until introduction of an effective vaccine. Symptoms are vomitting and watery diarrhea, which can dehydrate infants quickly. Children may recover in 24 hours. Caused by rotavirus. Often it can spread on ships due to uncooked seafood, and packed quarters. There are two rotavirus vaccines for infants.
question
Secreted glycoprotein (sGP)
answer
An open reading frame in the Ebola virus genome. Encodes a major secreted glycoprotein, the fourth least numerous polypeptide. May reduce the effectiveness of the immune system.
question
Shingles
answer
A disease caused by varicella zoster virus in older hosts. Symptoms include painful, itchy rash on the torso.
question
Sialic acid
answer

Neuraminic acid

Influenza virus attaches to the receptor for sialic acid.

question
Sigla
answer
A nomenclature system for viruses. Viruses are named using acronyms. Example: picornavirus (pico-RNA-virus).
question
Signal peptidase
answer
A peptide that cleaves the Zika polyprotein.
question
Signal sequence
answer
Localizes a protein to where it needs to be in the cell.
question
Simeon Ecuyer
answer
A British captain who distributed two blankets and some handkerchiefs inoculated with smallpox as gifts to Native Americans.
question
Simian virus 40 (SV40)
answer
A virus that uses the host's DNA polymerase, which is not produced by the cell unless it is replicating. The virus produces a protein that causes the cell to proliferate and produce DNA polymerase. Used as a model because it is large, simple, and easy to replicate. It produces a lot of mRNA, so it is easy to detect and isolate its mRNA. While studying it, scientists discovered 5' capping, poly-A tails, and nuclear locator signals. It can be used to make vaccines. It has only one capsid protein, a penton. The viral DNA is wrapped in histones so that it resembles cellular DNA. It steals cellular histones as part of its virion structure.
question
Simple viruses
answer
Viruses with fewer genes
question
Single stranded DNA (+ssDNA)
answer
A type of DNA virus. Has relatively simple structure. Limited on how large the genome can be. The +DNA is transcribed into dsDNA then into mRNA. The +DNA is transcribed into +DNA for genome replication.
question
Single stranded RNA (ssRNA)
answer
A type of RNA virus. Can be positive or negative sense, and non-segmented or segmented.
question
Skin
answer
A portal of entry. The skin must be broken to cause infection. Poxvirus can infect through this point.
question
Spanish flu
answer

French flu

A disease that caused the Great flu pandemic, and changed the fate of WWI. It affects young people, such as those who were involved in the war.

question
Sparta
answer
During the Trojan wars, Achilles fought on this side.
question
Species
answer

" _ virus"

A taxonomic level. There are 2827 species of virus.

question
Spruce budworm baculovirus
answer
Can be used for biological control of pests. There was an outbreak in Canada.
question
Strawberry virus
answer
A virus that affects strawberries, transmitted by aphids. In 2013 there was an outbreak in Nova Scotia.
question
Structural protein
answer
Proteins that form the virion.
question
Study groups
answer
Local groups which can make recommendations to the ICTV.
question
Subfamily
answer
A taxonomic level. Not all viruses have a subfamily. There are 22 subfamilies of viruses.
question
Subunits per turn (?)
answer

The number of subunits per turn of the helix.

P = ? x p

question
Subviral entity
answer
Similar to a virus, but not a virus. Has no other taxonomic home. Doesn't replicate the same way virsuses do. Includes satellites, viroids, virusoids, and prions.
question
Subviral genomes
answer

Non-viral genomes

Always ssRNA and circular. Includes virioides, satellites, and delta agents.

question
Sugar
answer
A type of molecule. Carbohydrates consisting of C, H, and O.
question
Sulfation
answer
A post-translational protein modification. Addition of sulfates to the polypeptide. Changes the character of a protein.
question
Surveillance
answer
Important for efforts to eradicate certain diseases from the world.
question
Susceptible
answer
A cell which has a receptor for the virus, and may become infected. Necessary for the virus to replicate.
question
Systematics
answer
The study of biological relationships and evolutionary history.
question
T-antigen
answer

Tumour antigen

Produced by polyomavirus. Prevents cancer protection mechanisms of the cell, causing unregulated cell growth and tumour genesis. It has a nuclear locator signal, and binds to and interferes with P53. Cells have many antigens and immune responses to T-antigen.

question
T4 bacteriophage
answer
A complex dsDNA virus in the family Myxoviridae. The head is 110 x 80 nm. The tail is 15 x 110 nm. The tail attaches to the bacteria surface. Genome is linear and circularly permuted.
question
Taconomy
answer
Science of classifications that make biological sense. Includes ICTV rules for classifying viruses. All taxonomic names are in italics.
question
Tegument
answer
Matrix of a herpesvirus. Important for the replication cycle.
question
Tobacco mosaic disease (TMD)
answer
A disease caused by tobacco mosaic virus. There are white necrotic lesions on the leaf surface of a tobacco plant.
question
Tobacco mosaic virus (TMV)
answer
An RNA virus that causes tobacco mosaic disease. The first virus to be discovered, and much of the initial research into viruses was using this virus. Helical shape, 18 nm in diameter, 300 nm long. Contains 2130 protein units, and 6390 ribonucleic units. Pitch is 2.28 nm. Each protein subunit attaches to three nucleotides. Has a rigid nucleocapsid. The virion is weak and brittle, and can be broken easily.
question
Togaviridae
answer
A family of viruses. Includes rubella.
question
Togavirus
answer
A genus of positive sense RNA viruses.
question
Topoisomerase
answer
A component for DNA replication.
question
Transcription
answer
A nuclear molecular process. A component of biosynthesis. The basis of Baltimore Classification. Copying of a nucleuc acid template (DNA or RNA) to make primary mRNA. Uses RNA polymerase, transcriptase. Viral mRNA synthesis mechanisms depend on the nature of the genome template.
question
Transcription factor VP30
answer
An open reading frame in the Ebola virus genome. Encodes viral protein 30 kDa, the third least numerous polypeptide.
question
Transformation
answer
After uncoating, there is integration of the viral DNA into the cell genome, causing transformation into tumour cells. The gene may be inserted in the genome near a cancer-causing gene. Retroviruses can do this.
question
Translation
answer
A cytoplasmic molecular process. A component of biosynthesis. Copying of codon triplets of mRNA, beginning with the AUG codon, to make a polypeptide. The cell's cytoplasmic ribosomes, as well as other components, are needed for translation. The ribosomes starts at the 5' end of the mRNA, and amino acids are added to the C terminus of the nascent polypeptide.
question
Transmission
answer
A criterion for demarcation of viruses into species. How the virus is transmitted. Includes coughing, mosquitoes, and ticks.
question
Triangulation number (T)
answer

Used to calculate the number of capsomeres or protomers of an isometric virus nucleocapsid. Generally, the larger the T value, the larger the virus, but this depends on the size of capsomeres.

Number of capsomers = 10T + 2

Number of protomers = 60T

question
tRNA
answer
A component for translation.
question
Tropism
answer
Virus specificity to certain cell types, such as lung cells. Necessary for the virus to replicate.
question
Troy
answer
During the Trojan wars, Hector fought on this side.
question
Tyrode's solution
answer
A mixture of salts used for tissue cultures.
question
U. Fisher et al
answer
In 1995, discovered nuclear export signals.
question
Uncoating
answer
The third sequelae of animal virus infection and virus replication. Common to all viruses. The virus uncoats, freeing the viral genome. Occurs in the cellular compartment where it needs to be uncoated.
question
Urogenital tract
answer

Penile, vaginal (including childbirth), and urinary

A portal of entry. Human herpesvirus, HIV, and HPV can infect through this point.

question
V.B. Reddy
answer
In 1978, fully sequenced SV40 dsDNA genome, the first "mammalian" genome, which has 5,224 nucleotides.
question
Vaccinia virus
answer
A complex RNA virus in the family Poxviridae. 200 x 200 x 250 nm in size. Has complex symmetry. Has a lateral body with an outer envelope, enclosing a nucleoid. Has its own enzymes for adding a 5' cap to its mRNA in the cytoplasm.
question
Varicella zoster virus
answer

Chickenpox virus

A virus in the family Herpesviridae. Causes chicken pox and shingles in older hosts. A vaccine was recently developed for it, which is free.

question
Vesicular stomatitis virus (VSV)
answer
A virus used as a base for the VSV-EBOV vaccine. In the same family as rabies virus.
question
Viral conjunctivitis
answer

Pink eye

Caused by adenovirus in the family Adenoviridae or by herpesvirus in the family Herpesviridae. A childhood virus which causes tearing, redness, itching, and crusty eyelashes. Caused by the same virus as the common cold. Often spreads in schools and day care centres. Most children recover in four to seven days.

question
Viral genes
answer
A criterion for demarcation of viruses into species. The genomes and proteomes of a virus.
question
Viral genome
answer
Has limited coding capacity, so many copies of the same protein may be used for the capsid.
question
Viral protein 0 (VP0)
answer
A viral protein of poliovirus which is equivalent to VP2 and VP4 still not cleaved from each other. The virus is not infectious until VP0 is cleaved into VP2 and VP4; this occurs in a maturation phase.
question
Viral protein 4 (VP4)
answer
A viral protein of poliovirus. An internal structure protein. It is initially part of VP0.
question
Viral protein genome linked (VPg)
answer
Attached to the 5' end of poliovirus +RNA, acting as a primer for translation, binding to the ribosome in several places. It falls off the mRNA during translation. It is cleaved off of in the nucleus for genome replication. It is uridylated, making a poly-U tail.
question
Viral proteinase (pr)
answer
A component of the Zika virus virion.
question
Virion
answer
A complete mature infectious virus particle. The physical virus particle, which can be seen. Often symmetrical shape. Consists of the nucleocapsid and envelope. Made up of nucleic acids, proteins, lipids, and carbohydrates.
question
Viroid
answer
Has a subviral genome.
question
Virus
answer
Obligate intracellular parasite. Cause many infectious diseases, which may have influenced history. They can help to unravel molecular and cellular structures/processes, and can be harnessed for biotechnology. They may be considered living things, but this is debated. Their bodies are more numerous than any organism, and they are too small to be visualized in a light microscope. Can be serially passaged despite dilution. The components of a virus can crystallize spontaneously to form the virus. Small, soluble particles, less complex than bacteria or fungi, but more complex than a molecule. Contain DNA or RNA covered by a protein shell, and may have an envelope. They cannot be grown on a non-living surface; must have living cells in which to replicate and form a plaque. Host cells are used for energy metabolism, protein synthesis, membrane biogenesis, and cellular scaffolding, a virus replicates by synthesis of viral macromolecules and self-assembly. They are filterable infectious agents; can be separated from larger microbes such as bacteria and fungi. Originally they were not known, and could not be isolated or detected.
question
Virus isolate
answer

Virus strain, type, serotype, subtype, variant, or genotype

Naming of different viruses. No taxonomic significance to the ICTV.

question
Virus latency
answer
After uncoating, the virus goes into a dormant state, and stimulus such as a hormone activates it to undergo lytic cycle.
question
Virus name
answer
Not written in italics. The real thing, which you can put in a test tube and study. Has no taxonomic significance; not bound by rules.
question
Virus replication cycle
answer

Attachment, penetration, uncoating, biosynthesis, assembly, release, and maturation.

mnemonic: APUBARM

question
Virus species
answer
Written in italics. The basic unit of virus taxonomy. A man-made abstract concept for organizing virus for purposes of communication and classification.
question
VPg uridylation
answer

Addition of uridines to the VPg of poliovirus. Creates a poly-U tail which can be transcribed to create a poly-A tail.

VPg + U > VPgU

question
VSV-EBOV vaccine
answer
A vaccine against Ebola which uses vesicular stomatitis virus as a base. Developed at the National Microbiology Laboratory in Winnipeg. The VSV G envelope protein is exchanged with EBOV GP envelope protein. When introduced to the body, the immune system produces Ebola GP antibodies. This vaccine was used during the Ebola outbreak in Africa.
question
Wendell M. Stanley
answer
In 1936, discovered that tobacco mosaic virus could be crystallized and viewed by electron microscopy. The crystals were still infectious. This is a chemical property; he thought the agent was a protein.
question
Walter Reed
answer

An American army surgeon who tested Carlos Finlay's theory that mosquitoes or filtered serum could transmit yellow fever, but not fomites. A "volunteer" (a soldier) died in one of his experiments in 1901. There were two buildings:

1. Closed and filled with fomites including blankets, clothes, and towels used by patients with yellow fever.

2. Lots of fresh air, with two sections: one protected by mosquito meshing, and the other exposed to mosquitoes.

Only volunteers exposed to mosquitoes developed yellow fever.

question
Walter Reed and James Carroll
answer
Discovered yellow fever in humans in 1901.
question
West Nile virus
answer
A virus that is transmitted by mosquitoes. It can become serious. Horses are a dead-end host, however mosquitoes can acquire the virus from humans.
question
Wilhelm Ellerman and Olaf Bang
answer
Discovered fowl avian leucosis in 1908.
question
World Health Organization (WHO)
answer
Attempted to control the spread of Ebola during the outbreak in 2014; administered quarantines and buried bodies in mass graves.
question
Yellow fever (YF)
answer
A disease caused by a Flavivirus. Discovered by Walter Reed and James Carroll in 1901. The first disease in humans discovered to be caused by a virus. There was an outbreak during the Spanish American war in Cuba and Panama in 1898, and the Spanish lost the war due to lack of immunity to the fever. It is transmitted by mosquitoes.
question
Zika
answer
An isometric positive sense ssRNA virus in the family Flaviviridae. Transmitted by mosquitoes. It spread from Uganda to Brazil, then to North America. The species of mosquito which spreads it lives south of Florida, and there haven't been any cases in Florida since August 2016. Greatest risk is to pregnant women; causes microcephaly in the fetus. Genome is 10,676 bp. Has one reading frame; the entire genome is translated into a polyprotein with several transmembrane domains, embedded in the endoplasmic reticulum. It is cleaved at specific sites. Components of the virion include C, pr, M, E, and NS 1 - 5. Peptides that cleave the polyprotein include signal peptidase, Golgi protease, and NS3 protease.
question
Zoonose
answer
A disease spread by more than one animal species, and may be transmitted to people.
Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New