Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Viral phylodynamics wikipedia , lookup
Social history of viruses wikipedia , lookup
Bacteriophage wikipedia , lookup
Endogenous retrovirus wikipedia , lookup
Oncolytic virus wikipedia , lookup
Virus quantification wikipedia , lookup
Plant virus wikipedia , lookup
Introduction to viruses wikipedia , lookup
Negative-sense single-stranded RNA virus wikipedia , lookup
Papillomaviridae wikipedia , lookup
Structure - genetic material (Either DNA or RNA, but never both) - Capsid- a protein coat that surrounds the genetic material Why are viruses considered nonliving? - They are not composed of cells. - They cannot reproduce independently (require a host). Can cause disease - Germ theory of infectious disease- disease can be caused by microorganisms (bacteria, viruses, protists). - Examples with DNA: herpes, chicken pox, flu, rabies, polio, smallpox - Specific to what they infect= they have target areas. Ex: a stomach virus that is inhaled will not infect a person. Other types of viruses 1. Oncogenic virus- cause cancer. Example= HPV (Human Papillomavirus) 2. Retroviruses- viruses composed of RNA. These infect the host’s genetic information and translate their RNA into the host’s DNA (so it works backwards), combining its code with that of the host. Example= HIV 3. Prions- protein infection particles. Example= Mad Cow Virus Cycles How do viruses infect your cells? Major difference, one waits and one destroys A. Lytic infection- the virus infects the cell by injecting its DNA. It then programs the cell to replicate the viral DNA repeatedly, until it causes the cell to burst. The new viruses then repeat the cycle with a new host cell. B. Lysogenic infection- the virus does not lyse (break open) the host immediately. Instead of taking over the host’s DNA, it combines its DNA with the host. As the host cell replicates and divides, it will pass on the viral DNA to the identical daughter cells. The virus will remain dormant until something triggers it to go into the lytic cycle. Vaccines- weakened or killed (torn apart) virus or viral proteins that you receive to build up your immunity. - The vaccine exposes you to the virus so your immune system will build up antibodies. - When you come into contact with the virus after vaccination, your antibodies will recognize it and attack it – so you should not get sick.