exam 2, chapters 26, 27, 28, 29, 30 Flashcards
viruses
very simple, made of DNA or RNA, no cytoplasm
3 types of viruses
RNA, DNA, retroviruses
virus structure
protein sheath or capsid, nucleic acid core
reverse transcriptase
RNA-> DNA, uses the host’s energy to turn RNA into DNA
tissue tropism
inside a host, the virus may only infect specific time
Viral replication
- infect a host cell
- the viral genome tricks the host cell into making viruses
- new viruses leave cells to infect other cells
replication is error-prone=
high rates of mutation
retroviruses
have single-stranded RNA genome that is transcripted to double-stranded DNA, reverse transcriptase
virus classification
taxonomy, genome classifications Baltimore classification, the host they infect, the disease they cause
taxonomy
uses order, family, subfamily, and genus
genome classification, Baltimore classification
are you DNA or RNA virus?
metagenomics
shows different kinds of viruses present
bacteriophages
viruses that can attack bacteria, very very small
lytic cycle
cut, break, delete the bacteria DNA, kill the cell
lysogenic cycle
the virus does not immediately kill the infected cell, it adds itself to its genome
lysogen
bacteria
viral infections
persistent vs. acute
persistent infections
latent or chronic
acute infections
latent or chronic
acute
rapid replication of virus and can lead to sudden symptom onset
HIV
destroying what is used to keep you healthy, acquired immune deficiency syndrome
latent viral infections
no symptoms, viruses that “hide” in the host
latent viral infections can be triggered
due to physiological stimuli (not eating, sleeping well)
prions
“proteinaceous infectious particles”, act like viruses, they misshape other proteins so that they wont function properly