8.1 Structural and Functional Diversity of Archaea

Question 1

ARCHAEAL MEMBRANE
▪ “lipid divide”
• ____ and _____
▪ evolution of
membrane proteins in response to the environment
▪ ________ drove the lipid divide.

Answer 1

Asgard and α-
proteobacteria

protein-lipid interaction

Question 2

ARCHAEAL MEMBRANE

____ bond
• thermotolerant
▪ chemical stability • stronger
intermolecular ______ bonding between the ______
• tight packing of _____

Answer 2

ether
hydrogen
headgroups
phospholipids

Question 3

ARCHAEAL MEMBRANE
________
• retains high
permeability at higher liquid crystalline plasma state
• omits the need to adapt
to environment change

Answer 3

isoprene

Question 4

ARCHAEAL MEMBRANE

______ of ______
• resistant to heat denaturation
• rigid membrane with low permeability

Answer 4

Monolayer
phospholipid

Question 5

What is the key feature of nearly all prokaryotic cells which maintains cell shape, protects the cell and prevents it from bursting in a hypotonic environment?

Answer 5

cell wall

Question 6

ARCHAEAL CELL WALL

______ (Paracrystalline protein surface layer)
▪ prevents osmotic lysis (i.e. Halobacterium salinarum), high temperature, low pH
▪ selective sieve for low-molecular-weight solutes

Answer 6

S-Layer

Question 7

ARCHAEAL CELL WALL

______ has a very limited distribution amongst archaea, only found in some methanogens like Methanobacteriales and Methanopyrales.

Answer 7

Pseudomurein

Question 8

ARCHAEAL CELL WALL

_______
▪ encloses the groups of cells in filaments to provide stability against detergents and proteases (Methanospirillum hungatei)
▪ filamentous Archaea

Answer 8

Protein sheath

Question 9

ARCHAEAL CELL WALL

_______
▪ thick polysaccharide walls composed of polymers of glucose, glucuronic acid, galactosamine uronic acid, and acetate.

Answer 9

Methanochondroitin

Question 10

Jihyo is treating an Archaea infection with penicillin however few weeks after use, her condition did not
improve. Why is this?

Answer 10

Archaea are characterized by their broad-spectrum resistance to antimicrobial agents. In particular, their cell wall lacks peptidoglycan, making them resistant to antimicrobial agents interfering with peptidoglycan biosynthesis.