involves the chemical attraction and attachment of the virus to protein receptors on Hosts cell via proteins on tail fibers of phages.
The Phage penetrates the weakened hosts cell wall and cell membrane and injects it DNA, and this disrupts the host cells own DNA(broken up)
The phages DNA directs the cells metabolism to produce viral components-proteins and copies of the Phages DNA.
-Bacterial DNA is hydrolyzed into nucleic acids
useful for constructing viral genomes.
-Production of capsid proteins, viral proteins and
Is the assembly of newly synthesized viral components into a complete virion.
-Nucleic Acids are packed inside capsid
-Capsid is attached to tail
***UNTIL MATURATION IS COMPLETE, IT IS NOT A COMPLETE VIRUS!!
Mature infectious virion partices are released from Host cells to infect new hosts cells.
Is how long it takes to go from Adsorption to Release.
-(20 -40 min)
How many phages are released per bacteria.
Result in the transfer of viral genes to bacterial host (transduction)
Prophages'genes encode for production of protein that:
- Repress viral replication
- Provide "immunity" to infection by related phages.
- Produce Toxins (ex. C. botulinum, C.diptheriae)
*Ticking time bomb*
Can occur Spontaneously or in response to outside stimulation (eg. low iron concentration).
Prophage removes itself from bacterial chromosome and begins lytic-like process to produce new temperate phages
Attachment of spikes, capsid or envelope and
Penetrates via endocytosis or fusion
Uncoating is necessary when it comes into the cell
Replication of DNA genome occurs inside the Hosts Nucleus
How viruses cause disease?
occurs when animal viruses undergo Lysogenic replication or when hosts cell lacks materials for lytic replication, slower process and overtime it can reactivate and cause disease (ex. chickenpox to shingles ).
How viruses cause Disease?
Cytopathic effects (CPE)
effects are directly observable changes to infected cells resulting in abnormal functioning from non infected cells to infected cells.
'viral junk' that remains after infection has resolved(rabies leave junk behind)
-and can transform normal cells into cancer cells.
cells that are clumped together and cause a mass (measles)
a visually observable change
Cancer gene 'on'
Cancer gene 'off'
Epstein-Barr Virus (EBV)
Human Papilloma Virus (HPV)
Herpesviru 8 (HV8)
Hepatitis B Virus
Hepatitis C Virus
Is infectious and can cause mononucleosis and is assosiated with Burkitt Lymphoma and HodginLymphoma
can cause benignwarts and genitalwarts, and is associated with Cervical, Penile and OropharyngealCancer
growth in lymphnodes and is associated with Kaposi'sDisease
Hep B virus and Hep C virus
cause hepatitis and is associated with livercancer
Virus like agents
are small infectious singular, circular RNA molecules
does not produce proteins
pathogenesis is unclear
presently know to only infect plants
(ex. Potatoe Spindle Tuber disease)
Virus like agents that are small proteinious infectious particles that is resistant to heat, disinfectionand radiation.
they are sensitive to protein denaturing agents (soap) and can cause diseases in humans and animals.
(ex. Mad cow disease, chronic wasting disease)
an RNA virus genome in the form of mRNA is referred to as?
+ sense RNA
animal viruses differ from bacterial viruses by?
Release of animal viruses occur via lysis or budding; the release of bacterial viruses occur via lysis only.