Lecture 04 – Lipids and molecules
Learning outcomes
describe the major lipid components of cell membranes, (glycerophospholipids, sphingolipids and cholesterol) and be able
to explain features of these molecules that confer hydrophobic and hydrophilic qualities.
recognize and correctly name examples of the above classes of lipids and examples of fatty acids commonly found in
biological molecules.
understand the effects that unsaturation of the fatty acid components of glycerophospholipids confer on the physical
properties of these molecules.
describe membrane fluidity in molecular terms and identify characteristics of the components of membranes that influence
this factor.
Give a brief account of the permeability characteristics of the lipid bilayer to different classes of molecule.
Lipids and fats
Lipids: molecules in cells that are water-insoluble (hydrophobic) but soluble in organic solvents e.g.
Triacylglycerols (fats and oils)
Glycerophospholipids and other membrane lipids
Steroids and cholesterol
Dietary and storage lipids are triacylglycerols (neutral fats).
Hydrophobic molecules
Form droplets in water or aqueous environment.
Important energy storage molecules
Membrane lipids
, Polar amphipathic molecules.
The most common class of polar membrane lipid are phospholipids, mostly based on glycerol –
glycerophospholipids
Basic structure of glycerophospholipids compared to triacylglycerols
Instead of a third fatty acid we have a phosphate attached to a polar head group (labelled ‘amino alcohol’
here)
Polar head groups found in phospholipids
Amino alcohols
Learning outcomes
describe the major lipid components of cell membranes, (glycerophospholipids, sphingolipids and cholesterol) and be able
to explain features of these molecules that confer hydrophobic and hydrophilic qualities.
recognize and correctly name examples of the above classes of lipids and examples of fatty acids commonly found in
biological molecules.
understand the effects that unsaturation of the fatty acid components of glycerophospholipids confer on the physical
properties of these molecules.
describe membrane fluidity in molecular terms and identify characteristics of the components of membranes that influence
this factor.
Give a brief account of the permeability characteristics of the lipid bilayer to different classes of molecule.
Lipids and fats
Lipids: molecules in cells that are water-insoluble (hydrophobic) but soluble in organic solvents e.g.
Triacylglycerols (fats and oils)
Glycerophospholipids and other membrane lipids
Steroids and cholesterol
Dietary and storage lipids are triacylglycerols (neutral fats).
Hydrophobic molecules
Form droplets in water or aqueous environment.
Important energy storage molecules
Membrane lipids
, Polar amphipathic molecules.
The most common class of polar membrane lipid are phospholipids, mostly based on glycerol –
glycerophospholipids
Basic structure of glycerophospholipids compared to triacylglycerols
Instead of a third fatty acid we have a phosphate attached to a polar head group (labelled ‘amino alcohol’
here)
Polar head groups found in phospholipids
Amino alcohols
