domain archaea Flashcards
who discovered that we can put bacteria and archaea into 2 dif groups
Carl woese
list the domains in the 3 domain system
eukarya, bacteria, archaea
list the shared characteristics of archaea and bacteria
prokaryotic, no membrane-bound organelles, circular DNA molecule, cocci and bacilli are most common shapes, size is roughly the same
members of domain archaea are known as ___ (hint: think where they live)
extremophiles
why are archaea extremophiles
they’re lovers of extreme environments, ie hot/boiling water springs
T or F: all archaea live in extreme environments
false; some inhabit temperate and tropical soils and waters, and they’re part of our normal human flora
other than extreme environments, describe where archaea live
temperate and tropical soils and waters, and they’re part of our normal human flora
T or F: some archaea are capable of producing endospores that aid in their survival in harsh conditions
false; no archaeons have been known to produce endospores, only gram pos bacteria
how many phyla of archaea are there
3
T or F: no pathogenic archaea have been discovered
true
list the common structures found in both bacteria and archaea
PM, ribosome, inclusions, nucleoid, periplasmic space, fumbriae/pili, flagella, cytoskeletal elements
which structures do bacteria and archaea share, but have differences between
PM, ribosomes, nucleoid, fimbriae/pili, and flagella
describe how bacteria and archaea differ in the chemical structure of the PM
b: hydrocarbons of phospholipid attached to glycerol via ester linkage
a: attached via ether linkage
benefit of ether linkage in archaea phospholipids?
ether bond is more resistant to both chemicals and heat, so this helps the organism survive/live in extreme environments
describe how bacteria and archaea differ in the physical structure of the PM
b: unbranched fatty acids, bilayer
a: branched fatty acids, monolayer
benefit of archaea having branched fatty acids + monolayer?
branched = allows the ones that live in cold environments to have a fluid membrane
monolayer = more stable at higher temperatures
describe how bacteria and archaea differ in their ribosomes
both have 70S ribosome, but they differ in the types of rRNA and proteins that make them up
describe how bacteria and archaea differ in their nucleoid
some archaea are polyploid: multiple chromosomes or more than one copy
many archaea use histones while bacteria have NAPs to compact DNA
benefit of archaea forming nucleosomes via histones?
protects DNA from heat, prevents chromosome from denaturing
describe how bacteria and archaea differ in their pili
in archaea, there are cannulea and hami
structure of cannulae pili
hollow and tube like structure
function of cannulae
attach or keep cells together after cell division
structure of hami pili
grappling hook
function of hami
involved in attaching archaeons to surfaces
describe how bacteria and archaea differ in their flagella
thinner, not hollow, only some have hooks, no basal bodies, no Mot proteins at the base, uses ATP hydrolysis to move instead of PMF
T or F: all archaea have a cell wall
false; only some do
T or F: archaea cell wall is made of peptidoglycan
false; peptidoglycan is not a component
list the types of archaea cell walls
- S layer
- protein sheath over the S layer
- polysaccharide cell wall
- pseudomurein and S layer
- glycocalyx
what is pseudomurein
false peptidoglycan
how does pseudomurein differ from peptidoglycan
only has L amino acids instead of L and D, and NAM is not present (also different bonds join the backbone sugars together)
do penicillin and lysozyme affect archaea? why or why not
no, because there is no peptidoglycan cell wall in archaea
T or F; archaea have capsules
false; this is not common
