week 2, viruses and bacteria Flashcards
what is a genome?
- DNA or RNA
- single or double stranded
- linear or circular
- single or multiple piece
what is a capsid?
protein shell
what is a capsomere?
the protein subunit of a capsid
when a virus is helical it is…
rod-shaped
what is the different between an polyhedral virus and a complex virus?
a polyhedral virus is icosahedral while a complex has an icosahedral head and helical tail
can allow only parasites to replicate inside host cells
obligate intracellular parasite
true or false
viruses gain enzymes for making macromolecules
false
viruses lack enzymes for making macromolecules
this limits the number of species a virus can infect
host range
what is the lytic cycle?
a replicative cycle that ends in death of a host cell
what virus replicates ONLY by the lytic cycle?
virulent
when a virus uses lysogenic replicative style…
temperate
this type of bacteria defense is when not all cells in a population will have the exact same surface receptor protein to match virus (natural immunity)
genetic diversity
what are restriction enzymes?
bacterial enzymes that recognize foreign DNA and cut it
CRISPR - cas system
long-term targeted defense against specific viruses
what do cas nucleuses do?
search out and cut up any DNA identified in the CRISPR region
when bacteria evolves to avoid viral infection and viruses evolves to beat bacterial defenses…
evolutionary arms race
this virus has an envelope derived from the host cell
enveloped virus
this virus does not have an envelope
naked virus
a harmless derivative of a pathogen that stimulates immune system to mount strong defense against it
vaccine
an infectious nucleic acid with no protein coat
viroid
what is a prion?
infectious self-replicating protein, no nucleic acid
small nuclear DNA that can be shared between bacteria
plasmids
no organelles
DNA segments that can jump to different sections of the cell’s genome
transposons