Section 2B - Cell membranes (2B.1 Cell membrane structure: (Triglycerides…
Section 2B - Cell membranes
2B.1 Cell membrane structure:
Phospholipids structure and properties:
Consists of two fatty acid tails and a hydrophilic head.
Tail is hydrophobic - general skeleton structure of fatty acid - O=C-OH
Head is hydrophilic due to polar properties and contains a phosphate.
Is essentially a modified triglyceride.
Negative charge due to phosphate molecule.
Built in layers called surfactants - phospholipids paired up tail to tail heads on the outside side by side.
Surfactants allows to form bilayers
Controls fluidity of cell through the how saturated or unsaturated the membrane is. Meaning if it is more unsaturated it is the more fluid it is due to the double bonds increasing fluidity.
Triglycerides structure and properties:
Used as storage molecule for storing hugh amounts of energy.
Insulation and buoyancy.
Does not affect water potential
Has a hydrophilic and hydrophobic end.
Cholesterol structure and properties:
Has a 4 carbon ring.
Is an hydroxyl group (OH)
Is a polar molecule
Due to size it can sit within the phospholipid bilayer and increase strength and fluidity of the membrane.
Fluid mosaic model:
2B.2 - Diffusion: