Virus Flashcards
(21 cards)
All viruses are
Obligate intracellular parasites
2 animal viruses
- Foot and Mouth disease- first animal disease
2. Yellow fever- first human virus
Nucleocapsid
Repeating protein subunits called capsomeres
Core- dna/ rna
Capsid- protein coat
Particle size range for virus
18 (30)-300 nm
+ssRNA virus
Ready to be used to make a protein
-ssRNA virus
RNA needs to be copied into +ssRNA, needs RNA deep RNA Polymerase
Virus Replication steps
- Attachment
- Entry
- Transcription
- Translation
- Replication
- Assembly
- Release
Entry by 2 ways
- Receptor mediated endocytosis
2. Direct penetration of Plasma membrane
Nonenveloped viruses form
Pores/ disrupt the membrane
Enveloped viruses
Membrane fusion
Enveloped viruses cause a receptor conformation change by (2)
- Low pH
2. Receptor induced
HA protein in ______, which is an ______ virus is for ______
HA protein in influenza, which is an enveloped virus, is for Cell attachment and fusion
Which genomes MUST bring their own polymerase into cell
-ssRNA and dsRNA
DNA viruses rely on
Cellular RNA polymerase
ALL _____ need cells ribosomes
viruses
Release techniques (3)
Lysis
Weak lysis
Budding (only enveloped viruses)
1 step growth curve
Infects every cell at same time and dies at same time
Phases of the growth curve
- Eclipse- attach and uptake
- Exponential growth- replicate and assembly
- Plateau- cell death
Viruses are only alive when _______
In the cell
All viruses are ___________
Obligate intracellular parasites
Viruses are classified by 4
- Genome
- Structure
- Particle
- Replication