Chapter 4-Archaea Flashcards
What features do Archaea have in common with Eukarya?
gene encoding proteins, replication, transcription, translocation
What features do Archaea have in common with Bacteria?
genes for metabolism
What features are unique to Archaea?
unique rRNA gene structures, capable of methanogenesis
a highly diverse morphology, grow in anaerobic hypersaline, pH extremes and high temperatures, found in marine, arctic, and tropical temperatures
domain Archaea
What are the shape and size of Archaea?
similar to Bacteria, cocci and rods are common shape, no spirochetes or mycelial forms yet, branded and flat shapes
How do cell envelopes in Archaea differ from those in domain Bacteria?
S layer may be only component outside plasma membrane, some lack a cell wall, capsules and slime layers are rare
unique phospholipids, lack fatty acids and ester bonds, instead have ether linkages, monolayer of phospholipids, isoprene unites
archaeal cell membranes
How do Archaeal cell walls differ from domain Bacteria cell walls?
lack peptidoglycan, most have S layer, protein sheath external to cell layer
How does an Archaeal cytoplasm differ from that of domain Bacteria?
very similar, but they lack membrane enclosed organelles, may contain inclusion bodies, contain all usual components
not well understood yet in Archaea, composed of pilia protein, central lumen similar to bacterial flagella, adhesion mechanisms
pili in archaea
hollow, tube like structures on thermophilic surface, unknown function, form a network of multiple daughter cells
cannulae in archaea
What are some differences to the archaeal flagella?
they are thinner, more than one type of flagellin protein, they are not hollow, grow at the base and not the end
How do Archaea move?
directed movement like Bacteria (chemotaxis and taxis)