functional morphology of prokaryotes Flashcards
2 major structural differences between prok and euk
- prok have no defined organelles.
2. prok are generally much smaller in size.
structure of prok
simpler than eul.
nucleoid, not bound. sometimes have plasmid, have cell wall.
structure of euk
sometimes have cell wall depending on euk.
have ER, golgi, mt and true nucleus
how S/V ratio affects prok growth
larger SA/V ratio = outside interacting with more of enviro, more nutrients + greater concentration gradient.
why do euk want to be bigger w smaller s/v ratio?
eat other smaller cells, more complex + specialized. sacrifice growth for increased complexity.
what constrains sie of prok?
ribosomes = can be as small as few proteins, cell membrane + at least 1 ribosome. but need these 3 to function + be called bacteria.
morphologies of prok cells
coccus, rod, spirillum, filamentous, stalk, hypha, spirochete
spirochetes : 2 ex organisms
treponema pallidum (syphilis) + borrelia burgdorferi (lyme disease) -> drill into muscle cells + cause disease
vibrio - bent rod. ex organism?
vibrio cholerae = diarrhea
cocci, cluster or pair or chain or tetrad
cluster = staphylo, pais = diplo. chain = strepto. tetrad = sarcina
appendaged/budding
growth stalk attaches to surface.. or bud - pillus cell buds off until settles somewhere else.
filamentous
chloroflexus: photosynthetic, ancient
define monomorphic
one shape, observed in pure cultures
define pleomorphic
multiple shapes.
-chage during growth. response to enviro cues: sporulation (nutrient limitation)
example of pleomorphic organism?
arthrobacter sp. morphogenesis from rod to coccus during growth3
macromolecules in prokaryotes
protein. nucleic acid (dna in nucleiod; rna in cytoplasm), polysacch: cell wall + storage. lipids = cytoplasmic membrane, cell wall, storage
permeability barrier
prevent leakage + transport of nutrients in + out
protein anchor in bacterial membrane
site of proteins involved in transport, bioenergetics + chemotaxis anchored to function externally
three functions of bacterial membrane
permeabiltiy barrier, protein anchor, energy conservation
energy conservation in bacterial membrane
generation + use of pmf
membrane chemistry = ester vs ether
ester = bacteria + eukarya.
ether : archaea = isoprene chain, more complex + stable
archaea - monolayer vs bilayer
bilayer = two shorter chains. hydrophobic inside, hydrophilic inside. monolayer = one long chain with 2 hydrophilic parts. must move in one piece = harder to move
function of hopanoids?
rigidity to otherwise flexible membrane due to planar configuration
euk: cholesterol (three 6-memer, 1 5-member)
bacteria: diploptene (four 6-member, 1 5-member)
rate of transport for water, uncharged non-polar, charged non-polar
excellent; uncharged: fair; charged = extremely poor.