Viruses Flashcards
lytic cycle
one way a virus can reproduce that kills the host cell right away; this process is when viral genomes and viral proteins are made into new viruses that will be released from the cell once it lyses
transposons
segments of dna that can jump from one location to another in the cell’s genome; this is one possibility that scientists think could have been the original source of viral genomes
restriction enzymes
these recognize and cut up foreign DNA in bacteria; it is the defense mechanism of bacteria against viruses
retrovirus
rna viruses that do an rna –> dna information flow; use reverse transcriptase; an example of these is HIV
virus
infectious particle consisting of genes and a protein coat
capsomere
protein subunits of the capsid
prions
infectious proteins that typically attack the brain tissue; causes normal brain proteins to turn into the misfolded form and thus causes brain damage
vaccines
harmless variants of a pathogen that can stimulate the immune system to mount defenses against the actual pathogen
prophage
viral dna that incorporates itself into the bacterial genome
virulent phages
phages that replicate only by the lytic cylce
viral envelope
a component of viruses that only some viruses have; these are typically derived from the plasma membrane of the host cell
horizontal transmission
one way that plant viruses can spread is by the plant being infected from an external source such as insects or farm equipment
HIV
the virus that causes AIDS; this is a retrovirus
bacteriophage
a virus that infects a bacteria
Wendell Stanley
crystallized the TMV
lysogenic cycle
one way a virus can reproduce that does not kill the host cell right away; the virus can lay dormant in the genome of the host cell and just get replicated every time the bacteria divides
obligate intracellular parasite
the term that describes viruses since they can only replicate and function in a host cell
capsid
the name for the protein coat in a virus
plasmids
small, circular dna molecules that are separate from chromosomes, can replicate independently of the rest of the cell, and are occasionally transferred between cells; these are another possibility for the original source of viral genomes
reverse transcriptase
the enzyme that retroviruses use to go from rna back to dna
temperate phages
virues that use both lytic and lysogenic reproductive cycles
vertical transmission
when plant viruses spread the infection from parent to offspring; this can be done asexually or sexually using seeds
antibiotics
these can kill bacteria but are powerless against viruses
host range
the range of cells that viruses are able to infect
AIDS
the disease caused by the HIV virus
provirus
viral genome that is permanently inserted into a host cell’s genome
mobile genetic elements
plasmids and transposons are called this because they are able to move within the genome
viroid
one type of infectious agent that is smaller than viruses; naked rna; these demonstrate that it only takes a single molecule to spread disease; these infect plants
antiviral drugs
drugs that are given when a person gets infected with a virus; they interfere with viral nucleic acid synthesis
Adolf Mayer
he gets credit for discovering viruses; researched tobacco mosaic virus
