3. LIPIDS
DEFINITON:-
“ANY class of organic compounds that are fatty acids or their
derivatives and are insoluble in water but soluble in NON-polar solvents. They
include many natural oils, waxes, and steroids.”
4. CLASSIFICATION OF LIPIDS
SIMPLE LIPIDS
A simple lipid is a fatty acid ester of different alcohols and carries no other
substance. It Comprises Only Carbon(C) Oxygen(O) And Hydrogen(H).
COMPOUND LIPIDS
A COMPOUND lipid is a fatty acid ester of different alcohols and carries
Phosphorus(P),Nitrogen(N),& Sulpher(S) In addition to Carbon(C) Oxygen(O) And
Hydrogen(H).
DERIVED LIPIDS
Derived lipids are the substances derived from simple and
compound lipids by hydrolysis. These includes fatty acids, alcohols, mono glycerides
and diglycerides, steroids, terpenes, carotenoids.
5. CLASSIFICATION OF LIPIDS
SIMPLE LIPIDS COMPOUND LIPIDS DERIVED LIPIDS
They includes: They includes: They includes:
OIL phospholipids
FATS glycolipids
WAXES lipoproteins
Fatty acid Cholesterol
Saturated
Unsaturated
Bile acids
• Mono-
unsaturated
• Poly -
unsaturated
Sex hormones
Vitamin D
6. SIMPLE LIPIDS
OILS :-
OILS are the substances which are usually LIQUID at room temperature.
For example: COCONUT OIL,SUNFLOWER OIL etc.
FATS :-
FATS are the substances which are usually SOLID at room temperature.
For example: BUTTER,GHEE etc.
WAXES:-
Wax is a simple lipid that is an ester of a long-chain alcohol and a fatty
acid. The alcohol may be made up of 12-32 carbon atoms. These waxes can be
found in nature as coatings on leaves and stems of plants, and prevents the plant
from losing excessive amounts of water
7. COMPOUND LIPIDS
PHOSPHOLIPIDS
They are substituted fats containing in addition to fatty acid
and glycerol, a phosphoric acid residue, a nitrogenous base and other
substituents. Examples: phosphatidyl choline (Lecithin), phosphatidyl
ethanolamine (Cephalin), sphingomyelins, etc.
8. COMPOUND LIPIDS
GLYCOLIPIDS
Lipids containing carbohydrate moiety( a part) are called
glycolipids. They contain a special alcohol called sphingosine or sphingol and
nitrogenous base in addition to fatty acids but does not contain phosphoric acid
or glycerol.
These are of two types:
• Cerebrosides
• Gangliosides
10. LDL & HDL
LDL (low-density lipoprotein), sometimes called “bad” cholesterol, makes
up most of your body’s cholesterol. High levels of LDL cholesterol raise your
risk for heart disease and stroke.
HDL (high-density lipoprotein), or “good” cholesterol, absorbs cholesterol
and carries it back to the liver. The liver then flushes it from the body. High
levels of HDL cholesterol can lower your risk for heart disease and stroke.
11. DERIVED LIPIDS
FATTY ACIDS
THE carboxylic acid consisting of a hydrocarbon chain and a terminal carboxyl group, especially any
of those occurring as esters in fats and oils.
THERE are two types of fatty acids:
Saturated
Unsaturated
Saturated is Further divided into two types
LOWER FATTY ACIDS
HIGHER FATTY ACIDS
Unsaturated is FUTHER divided into two types
Mono-unsaturated
Poly-unsaturated
12. DERIVED LIPIDS
SATURATED FATTY ACIDS
The fatty acid having no double bond in it is called saturated
fatty acid .
FOR example : Acetic acid CH3COOH
Propionic acid C2H5COOH
Lower Fatty acids :
Those saturated fatty acid which contain 10 carbon or less number of
carbons are called lower Fatty acids.
Higher fatty acids :
Those fatty acids which contain more than 10 carbon atoms are
called higher fatty acids.
13. DERIVED LIPIDS
MONO UNSATURATED:
The fatty acids having only one double bond
(unsaturation) in its structure is called mono unsaturated fatty acid
For example : Oleic acid (18:1;9)
POLY UNSATURATED :
The fatty acids having more than one double bonds
(unsaturations) in its structure is called poly unsaturated fatty acid.
For example : Linoleic acid (18:2;9,12)
Linolenic acid (18:3;9,12,15)
14. DERIVED LIPIDS
Cholesterol
It is the most important sterol in human body .Its molecular formula is
C27H45OH .its structural formula is ;