Definitions

Question 1

Bacterial membrane

Answer 1

Hopanoids = Sterol-like components of the cell membrane
For strengthening
Fatty acids
Glycerol-fatty acid link = ester
Phospholipid bilayer

Question 2

Achaea cell membrane

Answer 2

Ether linkages between glycerol and isoprene (5 hydrocarbon)
The major lipids are glycerol diethers with phytanyl (20-C side chain) and diglycerol tetraethers with biphytanyl (40-C side chains)
The phytanyl from each glycerol are covalently linked to form a lipid monolayer (instead of bilayer)
Resistant to peeling apart

Question 3

Transport mechanisms

Answer 3

Simple transport
Group translocation
ATP-binding cassette (ABC) system

Question 4

Simple transport

Answer 4

A result of conformational changes 
3 mechanisms:
Uniporter
Symporter
Antiporter

Question 5

Group translocation

Answer 5

Compound chemically altered during transport
Proteins alternately phosphorylated and dephosphorylated until Enzyme IIc phosphorylates the sugar to be transported
Energy provided by an energy rich organic compound such as phosphoenolpyruvate
Family of proteins involved:
• HPr and Enzyme I: non-specific cytoplasmic proteins
• Enzyme II:specific for each sugar
– Enz IIa: cytoplasmic
– Enz IIb: lies on inner surface of membrane
– Enz IIc: integral

Question 6

ATP-binding cassette system

Answer 6

Three proteins are involved in transport:
– The periplasmic substrate binding protein
– A membrane transporter
– ATP-hydrolyzing protein
Typically display high substrate specificity
Often involved in uptake of organic compounds (e.g., sugars, amino acids), inorganic nutrients (e.g., sulfate, phosphate), and trace metals