week 2 Flashcards
(35 cards)
bacteria: size
- size is very small: 1-5
- it would only be bigger or have an odd shape due to predation or to aid infection
bacteria shapes
cocci, bacilli, vibrios, spirilla, spirochetes, pleomorphic
cocci
- spherical
—–ex: diplo- : divide and remain in pairs
strepto- : singular chain
staphylo- : like clusters of grapes
bacilli
rod shaped
vibrios
curved, comma shaped
spirilla
rigid spiral shaped
spirochetes
flexible spiral shaped
pleomorphic
variable in shape due to no cell wall
—– ex: helicobacter pylori: causes stomach infection and can be either in a coccoid or helix shape
bacteria physical features
from outside -> in
— pili, flagella, capsule, cell wall, plasma membrane, cytoplasm, ribosomes, nucleoid (no nucleus)
cell membrane is composed of what?
capsule, cell wall, and plasma membrane
plasma membrane characteristics
- semi-permeable, phospholipid bilayer
- hopanoids are included into this membrane for fluidity and stability
—– “hopanoids are paranoid abt water” aka they’re hydrophobic
cell wall composition
- peptidoglycan (alternating NAG and NAM sugars)
—– 1 thick pepti, teichoic acid(-) = gram(+) so
PURPLE
—– 1 thin pepti and 1 other outer
membrane connected by Braun’s
lipoproteins= gram (-) so
PINK or red
capsule and slime layer
- purpose of both is to make the cell water-resistant
- capsule: made up of polysaccharides and hard to come off, more effective, protects (phagocytosis, drying out, viruses, and detergents)
- slime layer: eases motility bc it’s slippery, easily removed so less effective
nucleiod
- not membrane bound
- 1 closed circular, ds DNA
-supercoiling
flagella
- long, slender, helps with motility,
- controlled by kinases, run counterclockwise, and tumble clockwise
- moves in an undulating fashion (wave-like)
endospores
- only those bacteria have it who are in survival mode due to harsh environment and nutrient depletion
- resistant to heat, UV radiation, gamma radiation, chemical disinfectants, dessication
- autoclaving (invented by Tyndall) kills the bacteria w/ endospores
- anthrax: found in soil. ex: honey
pili
- short hair-like
- sex pili- longer, fewer, horizontal gene transfer
- moves in 2 phases like with oars
chloroplasts
site of photosynthesis
hydrogenosomes
found in anaerobic protists and the ATP is made by fermentation
Archaea: size
big: 0.2- 30mm
archaea: shapes
cocci and rod shaped
archaeal cell envelope
- some lack cell wall
- plasma membrane
- s-layer: may be the only layer on top of the plasma membrane and is thick bc the bacteria will be dunked into bad things
archaeal: membrane
- unique
- some have a monolayer
- ether linkages instead of ester linkages like b and e
archeal: pili
- cannulae: hollow, tube-like
- HAMI: like grappling hooks
