M7 INTRO Flashcards
VIRUSES
small infectious agents:
size
20 to 300nm
- Small infectious agents (20 to 300 nm)
- Contain only one kind of nucleic acid (DNA or RNA)
- Obligate intracellular parasites (they cannot replicate outside the cells)
- Responsible for a number of dreadful diseases in humans like Spanish flu (1918), Polio, SARS, Ebola, COVID-19 Pandemic (2020)
- Called as filterable agents (they can pass through the membrane filter)
VIRUSES
VIRUSES
contain what kind of nucleic acid
either DNA or RNA but never both
VIRUSES
type of parasites in terms of replication
obligate intracellular
they must enter a cell to replicate
VIRUSES | TYPES OF SYMMETRY
determines the symmetry
CAPSID
VIRUSES | TYPES OF SYMMETRY
20 triangular phases
cubic symmetry with icosahedral pattern
VIRUSES | TYPES OF SYMMETRY
symmetry is coils
helical symmetry
VIRUSES | TYPES OF SYMMETRY
with complicated symmetry
complex structures
VIRUSES | VIRAL PROTEINS
- Facilitate transfer of the viral nucleic acid
- Protect the genome
- Attachment of the virus particle
- Determine structural symmetry
STRUCTURAL PROTEINS
VIRUSES
- Determines the antigenic characteristics of the virus
- Some viruses carry enzymes to initiate viral replication
VIRAL PROTEINS
VIRUSES | VIRAL PROTEINS
Determines the ____ of the virus
ANTIGENIC CHARACTERISTICS
VIRUSES | VIRAL PROTEINS
Some viruses carry enzymes to ____
INITIATE VIRAL REPLICATION
VIRUSES
DNA virus
RNA viruses
viral nucleic acids
VIRUSES | VIRAL PROTEINS
what protects the genome
CAPSID
VIRUSES | VIRAL NUCLEIC ACIDS
- can be single- or double- stranded
- only agent that can be single- or double-stranded
DNA virus
VIRUSES | VIRAL NUCLEIC ACIDS
- as a single molecule or in several pieces (segmented);
- e.g., influenza and rotauis virus (segmented)
in pieces
RNA viruses
VIRUSES | VIRAL NUCLEIC ACIDS
____ RNA can directly undergo translation
positive
VIRUSES
- A lipid-containing membrane that surrounds some virus particles.
- It is acquired during viral maturation by a budding process through a cellular membrane
- contain glycoproteins
VIRAL ENVELOPE
VIRUSES | VIRAL ENVELOPE
A ____ that surrounds some virus particles
LIPID-CONTAINING MEMBRANE
VIRUSES | VIRAL ENVELOPE
It is acquired during viral maturation by a ____ through a cellular membrane
BUDDING PROCESS
VIRUSES | VIRAL ENVELOPE
contains ____
GLYCOPROTEINS
VIRUSES | VIRAL REPLICATION
Not all infections lead to a ____
PROGENY VIRUS
VIRUSES | VIRAL ENVELOPE
viruses that do not have envelope
NAKED
VIRUSES | VIRAL ENVELOPE
all ____ viruses have envelope
helical
VIRUSES | VIRAL ENVELOPE
icosahedral
either enveloped or naked
VIRUSES | VIRAL REPLICATION
a new viral particle formed after replication
PROGENY VIRUS
VIRUSES | VIRAL REPLICATION
____ result in the production of
progeny virus
PRODUCTIVE INFECTIONS
VIRUSES | VIRAL REPLICATION
____ fail to produce infectious
progeny
ABORTIVE INFECTIONS
VIRUSES | VIRAL REPLICATION
STEPS IN VIRAL REPLICATION
- Attachment
- Penetration
- Uncoating
- Expression of Viral Genomes and Synthesis of Viral Components Maturation virion
- Morphogenesis (or maturation) and Release
VIRUSES | VIRAL REPLICATION
a mature viral particle
VIRION
VIRUSES | VIRAL REPLICATION
Attachment of a virion to a s____ on a cell
SPECIFIC RECEPTOR SITE
VIRUSES | VIRAL REPLICATION
Penetration by ____
RECEPTOR-MEDIATED ENDOCYTOSIS
VIRUSES | VIRAL REPLICATION
direct penetration or fusion
with ____ envelop
PLASMA MEMBRANE
VIRUSES | VIRAL REPLICATION
in PENETRATION, the virus will be enclosed in an ____
endosome
VIRUSES | VIRAL REPLICATION
where the viral nucleic acid is physically separated from its protein coat
UNCOATING
VIRUSES | VIRAL REPLICATION
MORPHOGENESIS & RELEASE:
Non-enveloped viruses are released by
LYSES
VIRUSES | VIRAL REPLICATION
MORPHOGENESIS & RELEASE:
Enveloped viruses are released by
BUDDING
VIRUSES | VIRAL REPLICATION
morphogenesis is also called
maturation
VIRUSES | VIRAL REPLICATION
viruses can replicate in ____ or ____ of the host cell
nucleus or cytoplasm
- a virus that can infect bacteria
- has head & tail
bacteriophage
VIRUSES | VIRAL REPLICATION
Viral replication process of BACTERIOPHAGE
Attachment
Penetration (DNA is injected)
Biosynthesis
Maturation
Release
VIRUSES | ATYPICAL VIRUS-LIKE AGENTS
composed of a viral nucleic acid and proteins but cannot replicate without a helper virus, which provides a missing action
DEFECTIVE VIRUSES
VIRUSES | VIRAL NUCLEIC ACIDS
____ RNA cannot directly undergo translation
negative
VIRUSES | ATYPICAL VIRUS-LIKE AGENTS
an example of defective virus
HEPATITIS D
VIRUSES | ATYPICAL VIRUS-LIKE AGENTS
what is the helper virus of Hepatitis D
Lepa B adenovirus
VIRUSES | ATYPICAL VIRUS-LIKE AGENTS
- contain the host’s DNA instead of the viral DNA within the capsid
- can infect but cannot replicate
PSEUDOVIRIONS
VIRUSES | ATYPICAL VIRUS-LIKE AGENTS
an example of pseudovirion
Lepa B adenovirus
VIRUSES | ATYPICAL VIRUS-LIKE AGENTS
- consist solely of a single molecule of circular RNA without a protein coat or envelope
- targets plants
VIROID
VIRUSES | ATYPICAL VIRUS-LIKE AGENTS
- Infectious particles that are composed solely of proteins with no detectable nucleic acid
- TSF diseases
PRIONS
VIRUSES | ATYPICAL VIRUS-LIKE AGENTS
- “viruses-infecting bacteria”
- Transmissible spongiform encephalopathies
BACTERIOPHAGE