4

Question 1

Lipid structure

Answer 1

Structural components of cell membranes; they are amphiphilic possessing both hydrophobic (tails) and hydrophilic (head group) groups.

Question 2

Lipid layer functions:

Answer 2

Compartmentalization = Separation of numerous regions in the cell with different composition - compartments, separation between cell interior and environment
Barrier = Due to the low permeability for ions 
Adaptive = By changing the lipid composition the properties of the lipid bilayer can be tuned depending on the conditions of the environment – temperature, pressure, etc.

Question 3

Interaction with water:

Answer 3

water is pressed out of hydrophobic zone
minimal contact area
entropy of the lipid phase decreases
entry of water phase increases more