INTRO TO VIRO (MAAM T) Flashcards
found that the organism was small enough to pass through filter
Dimitri Iwanowski
virus in latin word is
poison
virus can reproduce only within _____
cells
characteristics of viruses
- contain a single type of nucleic acid, either DNA or DNa
- contain a protein coat (sometimes itself enclosed by an enveloped of lipids, proteins and carbohydrate) that surrounds the nucleic acid,
- multiply inside living cells by using the synthesizing machinery of the cell.
- cause the synthesis of specialized structures that can transfer the viral nucleic acid to other cells.
viruses lack enzyme for protein synthesis and ATP generation. To multiply, viruses must take over the ______ of the host cell
metabolic machinery
____ are too toxic for clinical use in virus
antiviral drugs
viruses infecting bacteria
bacteriophage
viral size
20 to 14,000 nm in length
a complete, fully developed viral particle composed of nucleic acid and surrounded by a protein cost that protects it from the environment and is a vehicle of transmission from 1 host to another.
virion
are nucleoproteins. they are non-cellular structures with infectious genetic material that may contain RNA or DNa but never both.
viruses
are capsid-encapsulated viruses with DNA or RNA molecules. it has nucleic acids well as protein layers.
virions
the function of virions is to deliver the _______ into the ______ so that the genome can be expressed (transcribed and translated) by the host cells.
dna or rna genome ; host cell
infectious RNA molecules
viroids
- are infectious protein particles, nucleic acids are absent
- are not viruses. they don’t contain genes.
prions
who names virus
Martinus Beijerinck
virions are produced in the cytoplasm of complex viral factories, _______
the virus
example of virions
Small Pox Virus, HIV, Coronavirus, Fluvirion
the ineffective form of a virus outside a host cell membrane with a nucleic acid core and a capsid and majority of this are non-infectious.
Virions
to create new virions, the proteins that will be incorporated into the virion are made through expression of viral genome and the virus genome is copied through the process of _____
replication
free RNA molecules of low molecular weight without any protein coat
viroids
viroids are (smaller or larger) than virus
smaller
viroids infects only ______
plants
basic structural components of a virus
- Genome or Nucleic Acid
- Capsid - protective protein coat
- Envelope - some viruses contain an envelop surrounding the nucleocapsid
- Enzyme - play a central role in the infection process.
prion diseases can affect both ____ and _____ ; sometimes spread by ________ products
humans and animals ; infected meat products
6 steps of virus life cycle
- Attachment
- Penetration
- Uncoating
- Gene Expression and Replication
- Assembly
- Release
the nucleic acid of the virus is surrounded by a protein coat called _____
Capsid
each capsid is composed of protein subunits called _____
Capsomere
In some viruses = single type of protein comprise the ______ and in other viruses, several types of protein may be present
capsomere
In some viruses, the capsid is covered by an _____ usually consisting a combination of ____, _____, & _____
envelope ; lipids, protein, and carbohydrate
depending on the virus, envelopes may or may not be covered by _____
spikes
carbohydrate-protein complex that project from the surface of the envelopes
spikes
used by some viruses to attach to host cells
spikes
has the ability to clump rbc
influenza virus
the resulting clumping of influenza virus is called ______
hemagglutination
in non-enveloped viruses, capsids are not covered by _____
envelope
in non-enveloped viruses, the capsid protects the nucleic acid from ______ in biological fluids and promotes the virus attachment to susceptible host cells
nuclease enzymes
Gen. Morphology of Virus
- Helical Viruses
- Polyhedral Viruses
- Enveloped Viruses
- Complex Viruses
virus classification is based on _______ which has been revealed by ________ and a technique called ________
thin capsid structure ; electron microscopy ; x-ray crystallography
resemble long rods which may be rigid or flexible
Helical Viruses
in helical viruses, the nucleic acid is found within a ____, ______ of a helical structure.
hollow, cylindrical capsid
example of helical virus
Rabies virus
many-sided virus
Polyhedral virus
many animal, plant and bacterial viruses are _____
polyhedral
in polyhedral viruses, the capsid is shaped as an ______, a regular polyhedron with __ triangular faces and __ corners
icosahedron ; 20 triangular faces and 12 corners
example of polyhedral viruses
Adenovirus, Poliovirus
a spherical (virus morphology)
Enveloped viruses
2 types of enveloped viruses
Enveloped helical - ex. Influenza Virus
Enveloped polyhedral - ex. Herpes Simplex Virus
particularly bacterial viruses have complicated structure. Ex: _____ - capsids with additional structures attached.
complex viruses ; bacteriophage
in complex viruses, the head is _____ and tail sheath is _____
polyhedral ; helical
example of complex viruses
pox virus
transmissible, untreatable, and fatal brain diseases of maamals.
prion diseases
the host’s normal ______ can, for unknown reasons, malfunction, and assemble into structural aggregates called _____ that causes infectious brain disease.
prion protein ; prions
prions mode of transmission
direct contact or indirectly through contaminated soil, found on water.
are non-living things because they don’t contain cells and do not have an energy metabolism system, no cell organelles and they are unable to carry out any type of metabolic activity.
Prions and viruses
prions and viruses reproduction
by recruiting the normal cellular isoform of the prion protein and stimulating its conversion into the disease-causing isoform.
viruses and prions can survive being ____, being treated with ____ and can still infect other brains years after they were transferred to a scalpel or other tool.
boiled ; disinfectants
the only human disease caused by a viroid
Hepatitis D
