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
what are common shapes of bacteria?
coccus, bacillus, spiral (spirochete/spirillum)
gram positive bacteria means…
can be stained by crystal violet due to thick peptidoglycan layer
gram negative bacteria means…
can not be stained by crystal violet due to extra lipopolysaccharide layer
what is a cell wall?
extra layer of peptidoglycan that surrounds cell membrane
what is fimbriae
shorter, hair-like extensions to adhere to surfaces
a sticky outer layer to adhere to surfaces, defense barrier
capsule
what is an endospore?
a tough bacteria spore that can resist damage and remain dormant
can survive UV radiation, desiccation, high temp, freezing, chemical disinfectants
what are appendages that join bacteria cells to exchange DNA
pili
this region of cytosol that contains the chromosomes
nucleoid
true or false
genetic recombination is horizontal gene transfer
true
what is the uptake of foreign DNA from the environment?
transformation
what is the uptake of foreign DNA via a virus?
transduction
conjugation is when…
DNA transfer between two prokaryotic cells via a pilus
how many genes are needed to form a pilus?
during the F factor
25
factor on a plasmid, can transfer conjugation ability to other cells is called
F Plasmid: F
antibiotic resistance is when…
genes that give bacteria ability to survive specific antibiotics
“self feeders” make their own food
autotrophs
what do heterotrophs do?
“eat others” consume material from living/dead organisms
anaerobic method to generare energy
fermentation
symbiosis
two different organisms living in close physical association
mutualism is when…
both parties benefit
commensalism is when…
one benefits, other is unaffected
parasitism is when…
one benefits, other is harmed
ex. pathogens
when chemicals are secreted by the bacteria out of the cell
exotoxin
chemicals in cell wall are released when bacteria dies
endotoxin
what is opportunistic infection?
commensal bacteria (one benefits, the other is unaffected) that take advantage of an opening
ex. staphylococcus aureus - flesh eating bacteria
what does MRSA stand for?
methicillin resistant staphylococcus aureus
a major phylum of gram-negative bacteria…
proteobacteria
this phylum contains escherichia (E. Coli), salmonella (stomach flu) and vibrio (diarrhea)
proteobacteria
this phylum has photosynthesis and carbon fixation
cyanobacteria
this phylum contains spiral gram-negative bacteria, treponema (syphilis)
spirochete
this phylum has extremely small parasites
chlamydiae
contains chlamydia
the phylum firmicutes contains…
endospore forming bacteria
staphylococcus, bacillus and clostridium belong to what phylum
firmicutes
crenarcheota bacteria are…
thermophile - live at high temp
acidophile - live at low pH (in acid)
this phylum produces methane from anaerobic fermentation and also live at high salt concentration
euryarchaeota
