Exam 1 Characterizing and Classifying Viruses Flashcards
Miniscule, acellular, infectious agent having either DNA or RNA
Virus
In order to grow, reproduce, etc viruses require this
A host
Protein coat of virus in extracellular state
Capsid
Protein coat surrounding a nucleic core
Virion
What is another term for a virion
Nucleocapsid
Once the virus is inside the host, the capsid is removed and exists as this
Simply as nucleic acid
Which types of organisms are susceptible to virus infection?
All types
What are the 3 viral shapes?
Complex
Polyhedral
Helical
This viral shape contains capsids of many shapes
Complex
This virus shape is spiral
Helical
This viral shape is a geodesic dome
Polyhedral
What is the most common shape of viruses?
Icosahedron (20 sides)
What shape is the rabies virus?
Bullet shaped
Where does the viral envelope come from?
Acquired from host cell
What are viral glycoproteins that project off the virus?
Spikes
Has envelope
Enveloped virion
No envelope
Non-enveloped or naked virion
How are viruses classified?
Based on type of nucleic acid, presence of an envelope, shape, and size
This type of viral replication usually results in death and lysis of host cell
Lytic replication
What are the 5 stages of lytic replication?
Attachment- to host cell Entry- of virion into host cell Synthesis- nucleic acids and proteins by the host's cells enzymes and ribosomes Assembly- of new virions Release- of new virions from host cell
In this form of viral replication, the infected host cells grow and reproduce normally for generations before they lyse
Lysogeny
This a bacteriophage capable of lysogeny
Temperate phages
This is an inactive phage, usually during lysogeny
Prophages
This form of viral replication can turn bacterium from harmless to pathogen
Lysogenic conversion
What are the two major differences of animal viruses?
Presence of envelope around SOME viruses
Lack of cell wall
What are the 3 mechanisms of entry of animal viruses?
Direct penetration
Membrane fusion
Endocytosis
In the replicaiton of membrane fusion, where do the viral glycoproteins go?
They remain in cytoplasmic membrane of host cell
What is it called when animal viruses remain dormant in host cells
Latent virus or provirus
What is the most common example of latent viruses?
Herpes
Viruses that cause cancer
Oncovirus
Uncontrolled cell division in multicellular animal
Neoplasia
Mass of neoplastic cells
Tumor (neoplasm)
Tumor that lacks ability to metastasize
Benign tumor
Cancer or tumors that can spread
Malignant
Extremely small, circular pieces of RNA that LACK CAPSIDS and attack plants
Viroids
Infectious, pathogenic RNA particles that LACK CAPSIDS and do not infect plants
Viroidlike agents
Proteinaceous infectious agents that lack nucleic acid
Prions
What do prions do to PrP proteins in a host
Change the PrP proteins from alpha helices to Beta sheets
Prion disease is most predominant where in a mammal?
Nervous system
Prions form large vacuoles in the brain known as what?
Spongiform encephalopathies
Name 3 spongiform encephalopathies
BSE- bovine or mad cow
vCJD
Kuru
