Download Viruses

Viruses
Virus Structure
• Nucleic acid
encased in a
protein coat
(capsid)
Viral Replication
• Only reproduce when
they enter a host cell
• They lack ribosomes
and enzymes
necessary for protein
synthesis and simple
metabolism
Viral Genome
Structure
•
•
•
•
dsDNA
ssDNA
dsRNA (reo)
ssRNA
– Serve as mRNA (+)
– Serve as template for
mRNa (-)
– Serve as template for
DNA (retro)
Bacteriophages
• Virsus that attack
bacteria
• Two types of
reproductive cycles
– Lytic
– Lysogenic
Lytic and Lysogenic Cycles
HIV is a Complex Animal Virus
• CD4 receptors
• Endocytosis
• Reverse
Transcriptase
• DNA Incorporation
• Produces genome
for new virus
• Assemble HIV
particles
• Exit by budding or
lysis
Treatment
• AZT – Blocks replication
• Protease inhibitors – blocks building of
capsid
Treatment
• Chemokines
• Blocking Receptors
• Defective HIV genes