Lipids are a heterogeneous group of compounds that are relatively insoluble in water but soluble in nonpolar solvents. They can be classified into simple lipids like fats and oils, compound lipids like phospholipids and glycolipids, and derived lipids which are hydrolytic products of other lipids. The main functions of lipids are to serve as storage for energy, act as structural components of cell membranes, and transport fat-soluble vitamins and cholesterol in the blood.

1. LIPIDS and their
classification

2. DEFINITION
The lipids are a heterogeneous group of compounds, including
fats, oils, steroids, waxes, and related compounds.
They have the common property of being
(1) relatively insoluble in water.
(2) soluble in nonpolar solvents such as ether and
chloroform.
(3)related more by their physical than by their chemical
properties.

3. SOURCES
ANIMAL
Animal fat ,meat ,butter ,milk ,cream ,ghee ,egg yolk ,liver
PLANT
Vegetable oil

4. CLASSIFICATION1
SIMPLE
LIPIDS
2
COMPOUND
LIPIDS
3
DERIVED
LIPIDS

5. SIMPLE LIPIDS
Esters of fatty acids with various alcohols.
FATS
Esters of fatty acids with glycerol.
Oils are fats in liquid state.
WAXES
Esters of fatty acids with higher molecular weight
monohydric alcohols.

6. COMPOUND LIPIDS
Esters of fatty acids containing groups in addition to an alcohol
and a fatty acid.
PHOSPHOLIPIDS
Lipids containing, in addition to fatty acids and an alcohol, a
phosphoric acid residue.
GLYCOLIPIDS
Lipids containing a fatty acid, sphingosine, and carbohydrate.
OTHER LIPIDS
Sulfolipids, amino lipids, lipoproteins

7. PHOSPHOLIPIDS

8. GLYCOLIPIDS

9. DERIVED LIPIDS
• THESE are hydrolytic products of above mentioned
compounds
• Lipoprotein
• Steroid
• Hormone
• Fatty acids
• Prostaglandin
• Glycerol
• Ketone bodies
• Aldehyde
• Fat soluble vitamins

10. FUNCTIONS OF LIPIDS
 Storage form of energy(9kcal/g)
 Important dietary constituents
 Components of fat-soluble vitamins
 Stored in adipose tissue , serves as a thermal insulator
 LIPOPROTEINS transport lipids in the blood.
 Role in pathophysiology of diseases e.g. obesity, diabetes
mellitus, atherosclerosis
 Role in nutrition and health.
 Structural components of biomembranes.

11. FUNCTIONS OF LIPIDS
 Metabolic regulator.
 Improve taste and palatability of food.
 Give shape and contour to body.
 Act as surfactant, detergents, emulsifying agents.
 Cushioning effect to internal organs.