biochemistry

1. Submitted by:-Mayur Pankhi Saikia
Department:-Bsc Biotechnology
Roll No:-8
College:-Asian Institute of Management and
Technology

2. ACKNOWLEDGEMENT
I would like to express my sincere respect and
gratitude to Dr Niren Deka Sir(Principal of
Aimt),Dr Monalisha Borah Saikia Mam(HOD of
Bioscience Department) and all other faculty
members .

3. Contents
 Introduction
 Definition
 Functions
 Classification
 Bibliography

4. INTRODUCTION
 The word lipid is derived from a greek word
“lipos”which means FAT.These are heterogenous
group of compounds.
 Unlike proteins,nucleic
acids,polysaccharides,lipids are not polymers
rather they are small molecules.
 They are the chief storage form of energy,besides
their role in cellular structure and other
biochemical functions.

5. DEFINITION
 Lipids are defined as compounds which are
insoluble in water and soluble in organic solvents
such as alcohol,ether,chloroform etc.
 They are the main constituents of plant and
animal cells alongwith carbohydrate and protein.

6. FUNCTIONS
 Lipids act as a reservoir of fuel.
 They are constituents of membranes and regulate
membrane permeability.
 They are source of vitamins(A,D,E &K).
 They are important as cellular metabolic
regulators (steroid hormones and
prostaglandins).
 They protect the internal organs ,serve as
insulating materials and give shape and smooth
appearance to the body.

7. CLASSIFICATION OF LIPIDS
 Lipids are broadly classified into
SIMPLE,COMPLEX,DERIVED and MISCELLANEOUS
lipids,which are further subdivided into different
categories.
 SIMPLE LIPIDS:-They are esters of fatty acids with
alcohols .They are mainly of two types
(a)Fats and oils:-These are esters of fatty acids with
glycerol.The difference between fat and oil is only
physical.The oil is a liquid while fat is solid at room
temperature.
(b)Waxes:-Esters of fatty acids with alcohols other than
glycerol.These alcohols may be aliphatic or alicyclic.Cetyl
alcohol is most commonly found in waxes.

8.  COMPLEX LIPIDS:-These are esters of fatty acids with
alcohols containing additional groups such as phosphate
,nitrogenous bases,carbohydrate etc.They are further divided as
follows-
(a)PHOSPHOLIPIDS:-They contain phosphoric acid and
frequently a nitrogenous base.This is in addition to alcohol and
fatty acids.
(i)GLYCEROPHOSPHOLIPIDS
(ii)SPHINGOPHOSPHOLIPIDS
(b)GLYCOLIPIDS:-These lipids contain a fatty acid ,carbohydrate
and nitrogenous base.The alcohol is sphingosine ,hence are also called
as glycosphingolipids.Glycerol and phosphate are absent.Eg:-
cerebrosides,gangliosides.
(c)LIPOPROTTEINS:-Macromolecular complexes of lipids
with proteins.
(d)OTHER COMPLEX LIPIDS:-Sulfolipids ,amino-lipids and
lipopolysaccharides are among the other complex lipids.

9.  DERIVED LIPIDS:-These are the derivatives
obtained on the hydrolysis of simple lipids and complex
lipids which possess the characteristics of lipids.These
include glycerol and other alcohols,fatty acids,mono – and
diglycerols,lipidsoluble vitamins ,steroid
hormones,hydrocarbons and ketone bodies.
 MISCELLANEOUS LIPIDS:-These include a
large number of compounds possessing the characteristics
of lipids.Eg:-carotenoids,squalene terpenes etc.
 NEUTRAL LIPIDS:-The lipids which are uncharged
are referred to as neutral lipids.These are momo-,di-
,triglycerols,cholesterol and cholesteryl esters.

10. BIBLIOGRAPHY
.Books- Biochemistry by Satyanarayan

11. THANK YOU