Virus Lecture 17 Flashcards
What was the phrase used to describe the first virus in regards to its ability to move through a mesh filter?
Contageum vivum fluidum
The first virus found?
Tobacco mosaic virus
What was the first animal virus filtered?
Foot and mouth disease
T:F Viruses are the most abundant type of biological entity.
True
They are found in almost every ecosystem on earth
What is a viruses size?
10^-7 m to 10^-8 m and need an electron microscope to see them.
Are viruses intracellular parasites?
Yes. They are obligate intracellular parasites.
T:F Viruses are sensitive to bacteria.
False
They are NOT sensitive to antibiotics
Are viruses are sensitive to interferon?
Yes
How do viruses gain energy?
They take over the host cellular metabolism.
T:F Viruses do not have specific hosts?
False
Most viruses are host specific
Virion
A complete virus particle that consists of an RNA or DNA core with a protein coat sometimes with external envelopes and that is the extracellular infective form of a virus.
Any aspect of the infectious agent and includes: the infectious (Virion) or inactivated virus particle
Virus
Why is the study of virology important?
Viruses cause high mortality and morbidity rates and some are zoonotic
What is a capsid?
The protein shell of a virus. It usually is symmetrical and used in identification
The basic subunit protein in the capsid of a virus is called?
Capsomer
Nucleocapsid is?
Capsid + Virus Nucleic Acid (DNA or RNA)/Genome
The lipid bilayer with embedded proteins that some viruses have is called?
Envelope
What does the envelope do?
Facilitates entry into host and may help with immune system evasion.
Virus Genome is either?
RNA or DNA
Nucleic acid is either?
RNA
DNA
Both, but at different life stages
Shape of nucleic acid
Linear
Circular
Segmented
Strandedness
Single
Double
Double with regions of single
Sense
Positive
Negative
Ambisense (+/-)
Positive sense viral RNA is similar to?
mRNA and can be immediately translated by the host cell
What sense viral RNA needs to be converted before translation?
Negative sense, it is complementary to mRNA
What are the DNA Viruses
Circovirus Parvovirus Hepadnavirus Papovavirus Adenovirus Herpesvirus Poxvirus (I need one of Nic's inappropriate acronyms here)
What steps must a virus go through to be successful?
Escape from the host or reservoir of infection
Transport to the new host
Entry to the new host
Escape from the new host
Vertical transmission
From mother to fetus or newborn at childbirth
Transmission between members of the same species?
Horizontal transmission
Cross species transmission
Transmission between species
Transmission between humans to animals or vice versa?
Zoonosis (anthropozoonosis)
Transmission of viral disease?
Person to person
Food and water (fecal-oral)
Insect vectors
Fomites (nonliving objects)
Steps virus replication
Attachment Penetration Uncoating Synthesis of viral nucleic acid and protein Assembly and maturation Release in large numbers
What are the four outcomes for a cell after viral infection?
Cell Death- Lysis, Alteration Cell Membrane, Apoptosis (cell suicide)
No apparent change to infected cell (Latent, Persistent or chronic infection)
Fusion of cells- multinucleated (viral syncytium)
Malignant Transformation (tumor)
Characteristics of nercrosis
Chromatin clumping Swollen organelles Flocculent mitochondria Disintegration Release of intracellular contents Inflammation
Characteristics of apoptosis
Mild convolution Chromatin compaction and segregation Condensation of cytoplasm Nuclear fragmentation Blebbing Apoptotic bodies Phagocytosis
