viruses Flashcards
viruses are NOT
living
viruses can’t live
on its own
viruses are not cells they are
infectious particles
obligate intracellular parasite meaning
to reproduces they need put DNA in cells
viruses anatomy
Nucleic acids (DNA and RNA) + protein coat (capsid)
some viruses have what else to thereanatomy
outer membranes
how do shapes of the virus relate
viruses are classified by shape and how they reprodouce
lytic cycle
burst to make more cells
lytic cells are virulent viruses meaning
lethal/deadly
lytic cycle is where viruses
destroy cells
virulent
virus with only a lytic cycle
steps of lytic cycle
1.Attatchment(absorbtion)
2. penetration
3.replicaiton
4.assembly
5.release
- attachment (lytic cycle)
-virus attaches to receptors on host cell wall
-happens with specificity ( lock and key)
- penetration (lytic cycle)
-Viral nucleic acid enters through plasma membrane —>host
-Capsid remains outside host
- Replication (lytic cycle)
Copy viral nucleic acid and proteins
- Assembly (lytic cycle)
New virus parts assembled
5.release (lytic phase)
-phage makes lytic enzymes to destroy host
-New viruses released
Lysogenic cycle (or dorment)
-can move into this cycle temporarily then move to lytic cycle
-Do not always destroy host
it hides
-Bacteria replicates all genetic material
prophage
loop of DNA combo of bacteria and reg cell is called a lysogenic cell
lysogenic
viral and host genomes become ONE 🡪 prophage (Lysogenic cell)
they coexist with cell
dorment
not actively making new viruses ( no bacteria material)
Lysogenic Conversion
(only for some types of bacteria
Lysogenic cells exhibit converts to new properties
reteroviruses
RNA virus
dsDNA into host genome
RNA polymerases transcribe incorporated DNA into copies of viral RNA
Viral proteins made
Capsid produced
New viruses assembled
Reverse transcriptase:
RNA→ DNA intermediate
transcription reversed
what type of retrovirus ex do you need tk
HIV
Emerging Viruses
New or previously uncommon
why do outbreaks of emerging viruses happen
Extend range-transporting viruses
High mutation rates
