a brief description of various stages of a life cycle of viruses.

1. From,
Meghana G S
M-Pharm

4.  Attachment
 Penetration
 Uncoating
 Gene expression & gene replication
 Virus assembly & release

5. PICTORIAL REPRESENTATION OF
VIRAL LIFE CYCLE:

10.  Required for replication of viral genome.
 Regulation of viral gene expression by activating
gene transcription
 Alters host cell metabolism
Once the viral genes have been expressed, viral
DNA is replicated & gives rise to new viral
genomes.
After the beginning of viral DNA replication, the
late genes are transcribed & translated to give
rise to late proteins which are the viral
structural proteins.

11. Once new viral genomes & proteins have been produced,
they are assembled into new virions. The viral genome is
then inserted into the capsid to form a nucleocapsid. The
nucleocapsid often assemble on the surface of cellular
membrane where viral envelope proteins are
concentrated. The virus then buds through the membrane
to give rise to enveloped viral particles. These particles
can then undergo maturation events to give rise to
infectious virus.
VIRUS ASSEMBLY & RELEASE:

12.  AGENTS INHIBITING VIRUS ATTACHMENT,
PENETRATION & EARLY REPLICATION:
Eg: amantidine, remantidine
 AGENTS INTERFEING WITH VIRAL NUCLEIC
ACID REPLICATION:
Eg: acyclovir, gancyclovir
 AGENTS INTERFERING TRANSLATION:
Eg:methisazone

13.  I am protein in nature,I catalyse the
transcription of early genes of virus who am
i?
Ans:RNA polymerase П & cellular transcription
factors
 I am a anti-viral drug,I inhibit the viral
nucleic acid replication who am i?
Ans:acyclovir, gancyclovir