Lipids are organic compounds that contain hydrocarbons which are the foundation for the structure and function of living cells.
Lipid molecules contain large hydrocarbon portion and not many polar
functional group, which accounts for their solubility behavior. Their
intermolecular interactions are dominated by the hydrophobic effect
and van der Waals interactions.
Lipids are water insoluble organic compounds. They are hydrophobic (nonpolar) or amphipathic
(containing both nonpolar and polar regions)
*Free fatty acids
*Triacylglycerols
*Phospholipids
*Glycolipids
*Steroids
Fatty acids are “carboxylic acids (or organic acid), often with a long
aliphatic tails (long chains), either saturated or unsaturated.” When a
fatty acid is saturated it is an indication that there are no
carbon-carbon double bonds and if the fatty acid is saturated it is an
indication that it has at least one carbon-carbon double bond.
Lipids are major components of cell membranes, and are
responsible for most of the permeability filter functions of
membranes. Membranes act as barriers to separate compartments within
eukaryotic cells, and to separate all cells from their surroundings.
A lipid abnormality is one of the causal factors of cardiovascular
disease. Excess LDL cholesterol (say a total serum cholesterol >
4-5mmol/L) is the most widely accepted risk factor for heart disease.
Excess triglycerides (say >1.8mmol/L) are probably important in CHD
but this is controversial. A low concentration of HDL cholesterol (say
less than 1.0mmol/L) is also accepted as a major risk factor.
What are lipids?
