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CH 19: Viruses - Coggle Diagram
CH 19: Viruses
ALL ABOUT VIRUSES
Characteristics: Small, Simple, Non-living (requires a host cell), SOME have membranous enevlope
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In some cases, a virus can develop a membranous envelope when existing the host cell, making it undetectable.
Each virus has a host range- a limited # of host species that it can affect, typically determined by the proteins on the surface
Zootonic diseases- a disease that can jump species, ex: swine flu
Prophage- phages DNA molecule integrates itself on the E.Coli chromosome.
Provirus- Newly made viral DNA enters the cell's nucleus and integrates into the DNA chromosome, permanently.
How they differ? Prophage is temporary, it leaves the host genome at the start of the lytic cycle.
Retrovirus- a single-stranded RNA that acts as a template for DNA synthesis, uses reverse transcriptase to copy their genome into DNA
Prions- infectious proteins that appear to cause degenerative brain dieases in animals. They are misfolded proteins that can be transmitted by food, act slowly, and virtually indestructible
EX: MAD COW DIEASE, SCARPIE
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Replicative cycles
Lytic Cyle: phage replicates; producing new phages then lyses out of host cell wall, releasing the virus.
Phages that only reproduce by lytic cylce are virulent phages
Lysogenic cycle- phages replicate with out destroying host cell, keeps multiplying until lytic cycle is triggered
Phages that reproduce by lytic and lysogenic cycles are Temperate phages
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