Doctor of Physical Therapy (DPT)
The University of Faisalabad
Classification of lipids
Fatty Acids: Chemistery, classification, occurance,
Triglycerols: structure and properties
Eicosanoids: classification and function
Cholesterol: Chemistry function and Clainical
Any of a group of organic compounds,
including the fats, oils, waxes, sterols, and
triglycerides, that are insoluble in water but
soluble in nonpolar organic solvents.
Oily to the touch.
And together with carbohydrates and
proteins constitute the principal structural
material of living cells.
Compound or complex lipids
Derived, precursor and associated lipids
Esters of fatty acids with glycerol
Also called neutral fats, triglyceride or
Esters of fatty acids with alcohols other than
Heigher mol. wt. monohydric alcohols
Esters of fatty acids containing group in addition
to an alcohol and fatty acid
Also called glycosphingolipids
Contain sphingosine, fatty acid and a
Hydrolitic products are sphingosine, fatty acids,
sugar units N-acetylehexosamine and Nacetyleneuraminic acid
Contain alcohol, fatty acids, phosphoric acid residue
and N-containing base
Hydrolitic compounds of simple and
Include diglycerols, fattyacids, alcohols,
sterols, vitamen D, E, K, Carotenoids, and v
fatty acid is a carboxylic acid with a
long aliphatic tail (chain)
carboxylic acid with a long aliphatic tail (chain)
Mostly have chain of even number of carbon atom
between 4 to28
derived from triglycerides or phospholipids.
When not attached to other molecules, known as
"free" fatty acids.
Saturated fatty acid
▪ Have no double bond between carbon atoms.
▪ saturated fatty acids are saturated with hydrogen
Unsaturated fatty acid
▪ have one or more double bonds between carbon atoms.
▪ can be saturated by adding hydrogen atoms to them,
converting the double bonds to single bond
Free fatty acids in organisms come
from breakdown of Triglycerides
Fatty acid is present in dietary fats i.e
Wheet germ oil
Fatty acids are important sources of fuel because,
when metabolized, they yield large quantities of
Many cell types can use either glucose or fatty
acids for this purpose.
In particular, heart and skeletal muscle prefer
Triglycerol or trigliceride is an ester derived
from glycerol and three fatty acids.
formed by combining glycerol with three
molecules of fatty acid
glycerol molecule has three hydroxyl (HO-)
Each fatty acid has a carboxyl group (-COOH).
hydroxyl groups of the glycerol join the
carboxyl groups of the fatty acid to
form ester bonds:
Main fuel store in body
Triglycerols are esters of the alcohol glycerol
reacting with fatty acids.
Triglycerols are the major form of Neutral Fat
found in nature.
Principal Fat found in foods, body tissues and
Eicosanoids are signaling molecules made
by oxidation of 20-carbon fatty acids.
They are clasified as,
A. Prostanoids▪ 1. Prostaglandins (PGs)
▪ 2. Prostacyclins (PGIs)
▪ 3. Thromboxanes (Txs)
B. Leukotriens (LTs)
B. Leukotriens (LTs)
Anti inflamatory action
A soft, waxy substance found among the fats in the
bloodstream and in all the body's cells.
Belong to steroid family
molecular formula is C27H46O
three regions: a hydrocarbon tail, a ring structure region
with 4 hydrocarbon rings, and a hydroxyl group
The hydroxyl (OH) group is polar, which makes it soluble in
4 hydrocarbon rings is signature of all steroids
Hydrocarbon tail is fat soluble region
Cholesterol is called amphipathic due to presence of both
water and fat soluble regions
required to build and maintain membranes.
modulates membrane fluidity over the range of
increases membrane packing, which reduces membrane
functions in intracellular transport, cell signaling and nerve
myelin sheath is rich in cholesterol that provide insulation
for effective impulse conduction
In the liver, cholesterol is converted to bile that aid in the
intestinal absorption of fat as well as fat soluble vitamens
A, D, E and K
Cholesterol is an important precursor molecule for the
synthesis of vitamin D and the steroid hormones
▪ strongly associated with cardiovascular diseas eg
atherosclerosis, myocardial infarction (heart
attack) stroke, and peripheral vascular disease
▪ Elevated cholesterol levels are usually treated with a
strict diet consisting of low saturated fat and low
▪ Abnormally low levels of cholesterol are
▪ linked with depression, cancer, and cerebral
Bile acids and salts
In the liver, cholesterol is converted to bile
stored in the gallbladder.
Bile contains bile salts
solubilize fats in the digestive tract
aid in the intestinal absorption of fat molecules as
well as the fat-soluble vitamins, A, D, E, and K.