Lecture 6A - Archaea Flashcards
- any large group of prokaryotes having unusual cell walls, membrane lipids, ribosomes, and RNA sequences
- having the ability to live in extreme environment where many microorganisms do not typically inhabit
Archaea
“Archaea are quite distinct from true bacteria and are though to have diverged from a common ancestral line at a very early stage, before the evolution of eukaryotic organisms”
Hoggs
Archaea are said to diverge from a common ancestral line at a __ __ __
very early stage
What does the term Archaea literally mean
Greek for ‘old ones’
some general facts of archaea
- not all need oxygen
- can produce ATP
- may survive temp. extremes
- may survive under rocks and oceal floor vents
- may tolerate huge pressure diff.
- live in communities of microorganisms
Archaeal cells surface structures acc. to Jarrell et al.
- entirely unique to Domain Archaea
- similar to known bacterial structures (with archaeal-specific twists)
- only superficially resemble appendages in bacterial domain with fundamental variations
examples unique surface structures of Domain Archaea
- hami
- cannulae
example of Archaeal structures similar to bacteria
pili
examples of Archaeal strcutures which only superficially resemble appendages found in bacterial domain
archaella (formerly archaeal flagella)
size of Archaea
slightly less than 1 µm long
shape of Archaea
- coccus
- bacillus
- some square and triangular
Used for locomotion of Archaea
archaella
hair-like structures that assist in movement of Archaea
archaella
how many archaella can attach to cell’s outer membrane
one or many
can also be found on the cell membrane of Archaea which allows cells to attach themselves in groups
protein networks
