Topic 2-L9 - Unique aspects of archaea cell Biology Flashcards
Evolutionarily, Archaea domain shares a more recent
common ancestor with
Eukarya than with Bacteria
Archaea DNA-related biology/processes (chromosome structure,
replication, transcription, translation) more similar to
eukaryotes than bacteria
Bacteria/Eukarya have
- Ester-linked lipids
- lipids that are fatty acids
Archaea have :
- ether linked lipids
- lipids are isopredoid
Archaea lipids contain
side branches and rings
Some archaea produce a
Lipid monolayer
Lipid monolayer
similar to bilayer, but lipid tails are joined
Archaea’s unique ________ ________ is thought to be important for its ability to survive harsh environments. More
robust structure.
membrane structure
Variation in how the cell wall for archaea is put together depending upon the
environmental niche
For majority of archaea – proteinaceous _________ act as the cell
wall
S-layers
Some archaea have a second
Membrane ( not like LPS in gram -)
Can some archaea lack cell walls all together ?
YES
So a small subset of archaea produce a cell wall that is similar to bacterial cell walls ?
Yes
Pseudomurein
- Makes up the cell wall that archaea produce.
Lacks D-amino acids, different
sugar linkage, NAM replaced with N-acetyltalosainuronic acid.
unique appendages have been found in some archaea
- Hamus
- Proteinaceous “grappling hook”
Hamus
fix cells to a surface or to other cells to mediate biofilm formation
Archaea swimming motility via an
analogous ______ _____ ________(but functionally/evolutionarily distinct)
flagellum-like apparatus
Known as archaellum
What is the archaellum powered by
Driven by ATP hydrolysis
Archaea motility filament built form
Inside out (opposite of flagellum)
Generally (not always) archaea swim
more slowly than bacteria.
An unusual (or typical?) archaea:
Haloquadratum walsbyi
Haloquadratum walsbyi
Extreme halophile: found in hyper-saline lakes with saturating salt levels
- produced PHA granules and gas vesicles
- diff mythology, thin square
Asgard archaea
Superphylum of Archaea –
multiple distinct sub-phyla have been identified (genome sequenced). Lokiarchaeota was first, found in marine sediments.
