Prokaryotes 3 Flashcards
what is symbiosis?
any two species having an intimate association
mutualism?
mutual benefit from the association
parasitism?
one member derives benefit at the expense of the other
commensalism?
associations that neither benefit nor harm either member
what can change all of the relationship’s organisms have?
changes to the environment
what is opportunistic infection?
a commensalistic bacteria becomes pathogenic in response to a changed environment
what factors affect the types of bacteria that are able to colonize our bodies?
- temp
- pH
- salt concentration
- available water
what does aerobic mean?
the organism requires oxygen
when did Earth’s atmosphere first become aerobic?
free oxygen started to accumulate in the atmosphere which marked the change from a reducing to an oxidizing agent
what are obligate aerobes?
organisms that need oxygen
what are obligate anaerobes?
no need for oxygen and may even be poisoned by it
facultative anaerobes?
can alternate their oxygen requirement
- uses oxygen if its available, but it doesn’t need it
what is a saprobe?
lives off decaying matter
phage?
virus that infects a bacterium
what does gram (+) and gram (-) bacteria have in common?
they both have plasma membrane
