Are viruses in the tree of life
No
Viral nucleic acid
RNA or DNA, single stranded or double stranded, and forward (DNA to RNA) or reverse (RNA to DNA which requires reverse transcriptase)
Viral genes
Only have essential genes so structural proteins, replications proteins, and attachment and entry proteins
Naked virus
Nucleocapsid - nucleic acid genomes and capsid proteins
Also have virus attachment proteins
Enveloped Virus
1nucleic acid genomes, 2capsid proteins, 3envelope with viral attachment proteins
Icosahedral
Like a soccer ball, can be enveloped or not
Helical
Long tube, always enveloped
Complex
Any shape not the other to, can or can not be enveloped
Viral reproduction
Requires a host cell, parasitic relationship
Viral life cycle
Attachment, entry, uncoating and replication, assembly, release
Two ways of entry
Encocytosis (cell brings virus inside through plasma membrane) or direct fusion (viral envelope fuses with host cell and contents are deposited inside)
Two ways or release
Lysis and budding
One antiviral medication and its target
Fostemasavir blocks viruses from entering a host
Viruses average size
.05 um
Antigenic Drift
Minor genetic change, mistake during RNA replication
Antigenic shift
Major genetic change, 1 host is infected with two viruses -> new strain
Enteric Viruses Transmission
Fecal- Oral
Respiratory Virus Transmission
Respiratory system or saliva
Sexually Transmitted Viruses
Sexual contact
Zoonotic Vires Transmission
Animal to human or vectors
Acute infections
Onset suddenly, short span, host cells usually burst and die, virus disappears after infection
Persistent Latent infection
Symptoms - none until reactivation, always infected, host cells are unharmed until reactivation, virus stays in host indefinitely but only grows during reactivation
Chronic Infection
symptoms - mild or absent, continueous low level viral production, host continually releases virus
Cancer developement
Occurs 15-20 years after infection, host grows into tumor, virus growth stops but viral genome remains
