week 1 - archaeal cell envelope

Question 1

archaea

Answer 1

• Single cell microorganisms
• Closer related to eukaryotes

Question 2

Archaeal cytoplasmic membrane lipids

Answer 2

glycerol diether
- ether linkage

diglycerol tetraethers
- ether linkage
-heads at bond end of molecules

crenarchaeal
- extreme environments
- ring structures

• The lipid tails are attached to glycerol via an ether linkage
• Lipids are “branched” with methyl (CH3) groups
  o Isoprenes
• Phytanyl (C20) or Bi phytanyl (C40)
• Crenarchaeal
  o Hydrocarbon moiety containing 5 and 6- carbon rings

Question 3

Architecture of the archaeal cytoplasmic membrane
lipid bilayer

Answer 3

• glycerol diethers
• C20

both extremely resistant to heat denaturation

Question 4

Architecture of the archaeal cytoplasmic membrane
lipid monolayer

Answer 4

• diglycerol tetraethers
• C40

one layer because have heads on each end
- makes them more rigid
- more heat resistant

Question 5

archaea
pseudomurein

Answer 5

• N-acetylalosaminuronic acid replaces NAM
• B(1-3) glycosidic bond replaced B(1-4)
• Lysosomes insensitive
• Different amino acids

Question 6

archaea
pseudomurein resistant?

Answer 6

Lysozyme resistant (one way to tell the difference)

Question 7

cell walls of archaea

Answer 7

• No peptidoglycan
  o Some have pseudomurein
• Other polysaccharide walls
• S-layers are common

Question 8

cell walls of archaea
- organised?

Answer 8

because dont have a cell wall, not very organised structure

nothing controlling the shape of teh archaea