Chapter 1 Flashcards
What is virus?
An infectious,obligate intracelullar parasite comprising genetic material DNA/RNA that surrounded by protein.
What is viriod?
Naked nucleic acid that endcode very few viral proteins.
-small pathogenic RNAs
-successful trans,it form plamt to plant
-Distinguish from vorus
-Doesnt need protein shell to protect it
What is visions?
Virus particles that infect host
Size of virus?
1.nanoparticles
2. Smallest = poliovirus
3.Biggest = Poxyvirus
Can be seen use electron microscope.
Can pass through filter because too small
How virus replicate?
Need to be inside host cell as they rely entirely to host cell ability to create energy to perform manufacturing process during replication.
Why virus need host cell to replicate?
- They lack of ribosomes :
-cannot synthesis protein
-need ribosomes to translate viral messenger RNA into viral protein - Cannot store energy in ATP.
3.Cannot synthesis basic building such as amino acid,nucleic acid and lipids
What is the causes of virus replication to host cell?
-host destruction because virus agent of disease
-Infect host by introduce nucleic acid and replicate your
What is infections?
Virus infect host cell by introduce their nucleic acid and replicate/reproduce.
Whatis transmission?
Infection from cell to cell
Virus infection steps?
- Attachment and inject viral genome into the cell
- Viral DNA integrates host genome
3.Replication of viral DNA amd synthesis of viral proteins
4.Viral particle release new
5.host dead
Two phases of virus
Extracellular and Inracellular
What is extracellular phase
Virus particles or virion are inert
What is Intracellular
Virus infect host cells and induce it to synthesis virions component and becomes complete virus
Other characteristics of Virus
- Their genome eother DNA/RNA but never both
- Aceluller (non cellular) because not make up from cell no cytoplasm and semi permeable membrane
3.lack of living things characteristic
Virus discovery?
1898,Loeffer and Frosh, foot mouth disease,agents replicate only in host
