EXAM 3: Chapter 4 Flashcards
Archaea size
generally 0.5-5 um in diameter
but varies greatly
Archaea shape
rods, spheres, spirals
irregular shapes
rectangular and square shapes (unique)
Archaea similar to bacteria
similar shapes
singular circular chromosome
lack membrane bound nucleus
Archaea similar to Eukarya
DNA is complex with histones
homologs of DNA replication enzyme transcription/translation machinery
Archaeal differences
live in some of most inhospitable places
organization and composition of PM
cell wall composition- lack peptidoglucan
Cell envelope of archaea
all have a plasma membrane
most have a cell wall
Plasma membrane differences
bilayer or monolayer
hydrocarbons (fatty acids) derived from isoprene units
hydrocarbons attched my ether linkages
Where are monolayered archaea found?
extreme temperatures
it is very rigid
Why is monolayer rigid?
because the tails are attached
Plasma membrane simularities
composition
Cell wall differences
Contain pseudomurein instead of peptidoglycan
b, 1-3 linkages
NAT instead of NAM
only have L amino acids
terminal amino acid is different
often, the S layer is part of the cell wall
archaeal cytoplasm
histones form structures that DNA wraps around
archaea: tetramer of histone
eukarya: octamer of histone
cytoskeleton
consists of same things as bacteria
What are Canulae
hollow glycoprotein tubes that link together to form a complex network
specific to archaea
T/F most archaea have capsules or slime layers
FALSE
Theories for canulae function
faster communication
way to share nutrients
Hami
surface structures made up of protein subunits
do form biofilms
Flagella similarities to bacteria
Look similar
rotate- counterclockwise is directed motion
Flagella differences
thinner and solid
composed of 2+ flagellin protein versions
likely grow from base than tip
hydolyzes ATP for energy (bacteria uses ion gradient)
spin clockwise to back up
T/F archaella and flagella are evolutionarily related
FALSE
convergent evolution
