Module 13: Viruses, Viroids, and Prions Flashcards
Virus is Latin for
Poison
What is the term for a group of viruses sharing the same genetic information and ecological niche?
Viral species
What was the first virus to be studied?
Tobacco mosaic virus
What type of microscope must be used to study viruses?
Electron microscope
What is the term for a completely developed viral particle?
Virion
Morbidity means
Sickness
Mortality means
Death
What is the term for the study of viruses?
Virology
What type of viruses can mutate and cause cancer?
Oncogenic viruses
What is a capsid?
The protein coat the surrounds the virus’ genetic material
Capsids are made of individual
Capsomeres
Where is the viral envelope found?
Outside the capsid
What structures of a virus help it attach to a host cell?
Spike proteins
What virus is responsible for 5-10% of upper respiratory infections in children, is non enveloped, and has a DNA genome?
Adenovirus
Does herpes have an envelope?
Yes
Does chicken pox have an envelope?
Yes
Does mononucleosis have an envelope?
Yes
Does West Nile virus have an envelope?
Yes
Does rabies have an envelope?
Yes
Does Hepatitis C have an envelope?
Yes
Does Influenza have an envelope?
Yes
Do mumps have an envelope?
Yes
Do measles have an envelope?
Yes
Does HIV have an envelope?
Yes
How is viral morphology determined?
Shape of the capsid
Name 3 viruses that have a helical capsid morphology
Ebola virus, rabies virus, and Influenza
What are the 3 types of capsid morphology?
Helical, polyhedral, and complex
What does icosahedron mean?
A polyhedral virus having 20 sides
What is the most common cause of gastroenteritis in the US?
Noroviruses
West nile, norovirus, adenovirus, poliovirus, HHV, and Zika virus are all examples of what capsid morphology?
Icosahedron
Give 2 examples of viruses that have a complex capsid morphology
Bacteriophages and pox viruses
What two conditions can pox virus cause?
Smallpox and cowpox
What virus is used to immunize against smallpox?
Vaccinia virus
What percentage of the US population suffers from a viral disease each year?
90%
What are the 5 steps in viral replication?
Attachment, entry/penetration, uncoating, biosynthesis, release
What part of the virus will connect with the receptor of the surface of the host cell?
Capsid spike
What are the two replication cycles that viruses can perform?
Lytic and Lysogenic
Describe the lytic cycle
Virus infects a cell, reproduces, and the cell dies when the virus is released
Describe the lysogenic cycle
Virus infects a cell, becomes part of the host cell’s DNA, host cell replicates with viral genome still inside- eventually one of those cells will enter the lytic cycle
All viruses can reproduce via the ______ cycle but only some can reproduce via the ________ cycle
Lytic; lysogenic
What did Esther Lederberg discover?
The lysogenic method of replication
What toxin is produced by Corynebacterium diphtheriae?
Diphtheria toxin
What toxin is produced by Streptococcus pyogenes?
Erythrogenic toxin
What toxin is produced by Clostridium botulinum?
Botulinum toxin
What toxin is produced by Vibrio cholerae?
Cholera toxin
What are the two methods that viruses can use to penetrate a host cell?
Endocytosis and membrane fussion
How to naked viruses exit a cell?
Lysis or exocytosis
How to enveloped viruses exit a cell?
Budding
What is the difference between the way a DNA virus replicated vs a RNA virus?
DNA viruses must go through replication, transcription, and translation
RNA viruses must only complete translation
What is the name of the enzyme that retroviruses rely on to help them turn their RNA into DNA?
Reverse transcriptase
What type of virus is and RNA virus and transforms its RNA into bacterial DNA?
Retrovirus
What method do we use to culture viruses in the lab?
Plaque method on a solid culture medium
What is the term for meaning “in a living organism?”
In vivo
What is the term for meaning “not in a living organism?”
In vitro
What is the most common method of animal virus cultivation?
Cell culture
What are the three formations of cell lines that animal viruses can be cultured in?
Primary, diploid, and continuous
What are the famous cells that came a woman with cervical cancer?
HeLa cells
How will transformed or infected cells will grow?
In a pile
What do we look for under a microscope to know that there is viral growth?
Cytopathic effects
What is the term for when multiple host cells fuse and create one big cell with multiple nuclei?
Syncytia
The presence of _______ _______ can indicate that a virus has replicated
Inclusion bodies
What are the 3 methods used to detect a virus in a clinical sample?
PCR, FA technique, and Serology
What are the y-shaped proteins that bind to antigens?
Antibodies
What type of virus causes Burkitt’s lymphoma?
Epstein Barr Virus
Where is EBV most common?
West africa
What virus causes lymph nodes, affected jaw, and can affect the nervous system?
Epstein Barr virus (EBV)
What virus can cause vaginal warts and cervical cancer?
Human Papillomavirus (HPV)
What is the term for a virus that can stay dormant in the body and present at a later time?
Latent virus
What virus causes chickenpox?
Varicella zoster virus (VZV)
What is the latent form of VZV?
Shingles
What is the new shingles vaccine that can be given at age 50?
Shingrix
What is the latent virus that can affect the mouth (causing cold sores) or the genitals (causing genital sores)?
Simplex virus (HHV)
What strain of the simplex virus affects the mouth?
HHV-1
What strain of the simplex virus affects the genitals?
HHV-2
Measles is also known as
Rubeola
German measles is also known as
Rubella
Which strain of measles is more severe?
Rubeola
What are the spots found in the mouth that are caused by Rubeola?
Koplik’s spots
How is measles transmitted?
Respiratory droplets
What is the term meaning that enough people have been vaccinated that case numbers are low enough that some people do not need to be vaccinated?
Herd immunity
What is R0?
The number of new cases that stem from one infected individual- tells the reproductive rate of a virus
If the R0 value is higher, the threshold for herd immunity must be ______
Higher
What are the 2 parts of the Influenza virus?
H and N
What does the H in the Influenza virus type stand for?
Hemagglutinin
What does the N in the Influenza virus type stand for?
Neuraminidase
What is the circular RNA molecule with single and double stranded sections that typically only infects animals?
Viroid
What is the only condition in humans known to be caused partially by a viroid?
Hepatitis D
What is the term for abnormally folded proteins that can cause disease?
Prions
Where are prion diseases commonly found?
In the brain
What is the condition that shows holes in the brain tissue?
Transmissible spongiform encephalopathy
What is the most common type of spongiform disease?
Creutzfeldt-Jakob disease
What is the only way to kill a prion?
Very high heat incineration
What is the term for when phage DNA is incorporated into the host cell’s DNA?
lysogeny