Diversity - Archaea & Bacteria Flashcards
(16 cards)
what do archaea and bacteria have in common
- prokaryotic (no nucleus and membrane-bound organelles)
- unicellular
- reproduce asexually by binary fission
conjugation
Under times of stress, DNA can be exchanged b/w 2 bacterial cells, which results in new genetic information
plasmid
carry genes and can be passed on
prokaryotic cells are classified based on:
size, shape, cellular respiration, nutrition, uses
archaea
- oldest group of living organisms
- thrive in extreme conditions (thermophiles, halophiles, methanogens)
- anaerobic
- heterotrophic (typically)
- not pathogenic
bacteria
- surrounded by peptidoglycan
- most are pathogenic
- live almost everywhere
Common shapes of bacteria
coccus (round), bacillus (rod), vibrios, spirillum, spirochete (spiral)
obligate aerobes
need o2 to survive
obligate anaerobes
cannot live in presence of o2
facultative anaerobes
prefer o2, but can live w/o it
helpful bacteria
some bacteria used in industry to make consumer products (e.g. cheese)
methanogens used to clean toxic sites, process called bioremeditation
harmful bacteria
pathogenic bacteria, many can be treated with antibiotics after the onset of the infection
ex. of diseases caused by bactera
impetigo, salmonella, pneumonia
antibiotics
chemical substances that inhibit the growth or kill bacteria
most are naturally produced by other living things
how antibiotics work
prevent formation of cell wall, so the cell fills w/ h2o, cell membrane ruptures, interferes with DNA synthesis
antibiotic resistance
can be passed from a resistant bacterium to a non resistant bacterium via plasmids during conjugation
