Lipids (phospholipids and cholesterol), proteins, and carbohydrates
Hydrophilic head
Consists of a phosphate containing group attached to a glycerol molecule
Hydrophobic tails
Contain either saturated or unsaturated fatty acid, are long hydrocarbon chains
Fatty acids is the cause of membrane fluidity since absence of double bonds increases fluidity
Membrane orientation retains during transfer between cell compartments due to specific proteins and lipid composition. Proteins like SNAREs and Rab proteins help membranes fuse correctly, preserving orientation.
Integral proteins
Are permanently embedded within the cell membrane
Peripheral proteins
Are attached to the surface of the membrane
Helping cells recognize each other and providing protection for cells is the function of carbohydrate coating on the membrane
Active transport
Requires energy for the movement of molecules
Passive transport
Does not require energy for the movement of molecules
Sodium potassium pump
Creates gradients of both sodium and potassium ions
