lipids

1. LIPIDS
Dr Asma Yaqoob

2. • A lipid is chemically defined as a substance that is
insoluble in water and soluble in alcohol, ether, and
chloroform.
• Lipids are an important component of living cells.
Together with carbohydrates and proteins.
• Lipids are the main constituents of plant and animal
cells.
• The functions of lipids include storing energy, signaling,
and acting as structural components of cell membranes.

3. • Examples of common lipids include butter, vegetable oil,
cholesterol and other steroids, waxes, phospholipids, and
fat-soluble vitamins. The common characteristic of all of
these compounds is that they are essentially insoluble
in water yet soluble in one or more organic solvents.
• Most people have high levels of fat in their blood because
they eat too much high-fat food.
• Some people have high fat levels because they have an
inherited disorder.
• High lipid levels may also be caused by medical conditions
such as diabetes, hypothyroidism, alcoholism, kidney
disease, liver disease and stress

4.  Triglycerides. Triglycerides are lipids you obtain from food sources of fat,
such as cooking oils, butter and animal fat.
 Non triglycerides. are a type of lipid that includes hormones and cholesterol.
 Complex lipids: Phospholipids, Lipoprotein

5. Fatty Acids
• Organic acid (chain of carbons with hydrogens
attached) that has an acid group at one end & a
methyl group at the other end

6. Fats esters of fatty acids with glycerol
Fatty Acids

7. Saturated and unsaturated Fatty acids
Saturated fatty acids have no double bonds in their long hydrocarbon chains.
COOH
COOH
COOH
COOH
COOH
Packed together  solid
They are solids at room temperature.
Stearic acid: CH3(CH2)16COOH

8. Unsaturated fatty acids have 1 or more double bonds (generally cis) in their long
hydrocarbon chains.
Saturated and unsaturated Fatty acids
They can not pack together
They are liquids at room temperature.
Oleic acid: CH3(CH2)7CH=CH(CH2)7COOH
Examples of unsaturated fatty acids are palmitoleic acid, oleic acid,
myristoleic acid, linoleic acid, and arachidonic acid. Foods containing
unsaturated fats includeavocado, nuts, olive oils, and vegetable oils such
as canola. Meat products contain both saturated and unsaturated fats.

9. • The human body is capable of synthesizing most fatty acids from
carbohydrates or other fatty acids.
Humans do not synthesize sufficient amounts of fatty acids that
have more than one double bond.
More than one double bond fatty acids are called essential fatty acids
and they must be provided by the diet.
Fatty acids
Linoleic acid linolenic acid

10. Saturated and unsaturated FA
Sat. Fatty Acids Formula Melting Point (o
C)
Butyric C4H8O2 Liquid
Palmitic C16H22O2 63
Stearic C18H36O2 70
Unsat. Fatty Acids Formula Melting Point (o
C)
Oleic C18H34O2 Liquid
Linoleic C18H32O2 Liquid
Linolenic C18H30O2 Liquid