Virus
Characteristics
previously, it was known as
= Contagious fluid
Contagium virum
fluidum
Virus (Latin)= Poison
(Filterable)small
Contains surrounding nucleic acid protein coat
contains single type nucleic acid (DNA)
(RNA)
complex
no enzymes for self metabolism
viral nuc.acid to other cellstransfer
obligatory intrcellular parasites
classified
Nucleic Acid
tDifferences structure @coa
Structure Nucleic Acid
-protein coat
-determined by viral nucleic acid
-each capsid composed of
capsomere
-some virus, capsid covered by
envelope
(eg: spikes)
Capsid & Envelope
-complete, fully developed infectious viral particles
Virion
General Morphology
Polyhedral Viruses
Enveloped Viruses
Helical Viruses
Complex Viruses
Classification
The sense (+ve/-ve) of ssRNA
Presence/Absence envelope
Nucleic acid strandedness
Type of host
Nucleic acid type
Vertebrates & other host
only @ vertebrates
invertebrates
plants
algae, fungi & protozoa
bacteria
Virus Family
DNA
RNA
most DNA viruses are released into
the nucleus of host cells
produce viral DNATranscription & Translation
Capsid protein synthesize @ cytoplasm
Adenoviruses
Herpesviruses
Papovaviruses
Hepadnaviruses
occurs @ Multiplication cytoplasm
the ds RNA
RNA-dependant RNA Polymerases synthesize
Picornaviruses
Togaviruses
Rhabdoviruses
Retroviruses
After maturation,
viruses released by // budding rupture in host cell
membrane
Bacteriophanges
Lytic Cycle
Lysogenic Cycle
Biosynthesis
Maturation
Penetration
Release
Attachment/Absorption
