Viruses Flashcards
Viruses
Cause diseases, damage living things, may be fatal
General characteristics
Very small, Various shapes, 2 part structure, Acellular, Have nucleic acid, Mutate very easily
Viruses size
10-1000 nanometers, need electron microscope to view
Viruses structure
Head, DNA, neck collar, sheath, base plate, tail fiber
Acellular means
no cell, no organelles, no metabolism, cannot be killed with antibiotics(antibiotics work by destroying cell membranes, viruses are not cells)
Nucleic acid
DNA or RNA
Mutate very easily
no cell, no protection from mutagens
Possible effects
Lyse cells, Release viral toxins, Prevent hosts cell division, Disrupt formation of host chromosomes, Uncontrolled cell division, Changes in cell membrane.
Cell lysis
Rupture of cell membrane resulting in the release of cell contents and death of a cell.
Viruses prevention
Vaccines( live or killed virus injected - host immune system makes antibodies - when infected, host immune system ready to kill virus)
Viruses treatment
Antiviral drugs, Supportive therapy
Antiviral drugs
interfere with viral replication, AZT for AIDS, Interferon for Hepatitis C, author Antonin Holy
Supportive therapy
reduce fever(aspirin, tamiflu), make host comfortable
Life cycle
Attachment on the host cellular surface, Penetration, Uncoating, Replication, Release the host cell by lysis
Types of viruses
1.RNA-DNA
2.Prions-Viroids
3.According to a host
