Description of the functions of glycolipids. Glycolipids are glycogen attached to lipid molecules

1. FUNCTIONS OF
GLYCOLIPID
PRESENTATION MADE BY
HETAKUMARI PILUDARIA
AND
PRERNA RANI
BSc (HONS) BIOTECHNOLOGY SEM I

2. INTRODUCTION
Glycolipids are derivatives of ceramides and
spingosine with carbohydrate directly attached to
ceramide.
HPILUDARIA
2

3. EXAMPLES
 Cerebroside
The simplest glycolipid
 Ganglioside
An example of complex glycolipid
HPILUDARIA
3

4.  Glycolipid plays important role in the following-
 Cell-cell interaction
 Structure of cell membrane
 Immune Responses
 Blood types
 Surface receptors
 Part of nervous tissue
 Part of Muscle tissue
 Cell Growth
 Diseases related to Glycolipid.
CONTENTS
HPILUDARIA
4

5. ROLE OF GLYCOLIPID IN CELL- CELL INTERACTION
 Serves as recognition sites for cell-cell interaction.
 Sugar moiety of glycolipid binds to a specific
complimentary carbohydrate.
 thus glycolipid acts as cell markers
HPILUDARIA
5

6. GLYCOLIPID IN CELL MEMBRANE
 Glycolipid in aqueous medium forms a bimolecular
sheet instead of micelle.
 Two fatty acids chains of glycolipid are too bulky to
fit into interior of micelle .
 And so it forms a bilayer similar to that of
phospholipid.
 The resulting hydrophobic interactions have three
significant biological consequences
HPILUDARIA
6

7.  The strong interaction between glycolipids and
cholesterol is the driving force which segregates from
the fluid phospholipid from the membrane
 The resulting hydrophobic interactions have three
significant biological consequences
o It has tendency to be extensive
o Tend to close on themselves so that there are no
edges with exposed hydrocarbon chains and so
form compartments
o Bilayers are self sealing because a hole in a bilayer
is energetically unfavorable.
HPILUDARIA
7

8. ROLE OF GLYCOLIPID IN IMMUNE RESPONSE
 Immune responses are generated when the
carbohydrate attached to the glycolipid binds to a
specific site of leukocytes and endothelial cells.
 Sugar moeity has special compliment binding sites
HPILUDARIA
8

9. GLYCOLIPIDS ARE RESPONSIBLE FOR
DIFFERENT BLOOD GROUPS
 Glycolipids are membrane components composed
of lipids that are covalently bonded to
monosaccharides or polysaccharides.
 One type of glycolipid found in human red blood
cells is involved in the ABO blood type antigens.
HPILUDARIA
9

10. HPILUDARIA
10

11. HPILUDARIA
11

12. HPILUDARIA
12

13. HPILUDARIA
13

14. GLYCOLIPID AS CELL SURFACE
RECEPTORS
 The carbohydrate part of the glycolipid have
particular binding sites
 Receptors will bind to the sugar part of the
glycolipid
HPILUDARIA
14

15. PART OF NERVOUS TISSUE
 Glycolipids are widely distributed in every tissue of
the body, particularly in the nervous tissue, such as
brain.
 They occur particularly in the outer leaflet of the
plasma membrane where they contribute to cell
surface carbohydrates.
 Gangliosides are present in nervous tissue in high
concentration and are associated with calcium ions.
HPILUDARIA
15

16. PART OF MUSCLE TISSUE
 Cerebrosides are present in large amount in animal
muscle tissue.
HPILUDARIA
16

17. CELL GROWTH
 Glycosphingolipids have been associated with
growth factor receptors
 Glycolipid interact with growth factor receptors
HPILUDARIA
17

18. DISEASES RELATED TO GLYCOLIPIDS
 Certain diseases are caused due to the abnormal
quantities of glycolipids in animal tissues, especially
in central nervous system.
HPILUDARIA
18

19. GANGLIOSIDE STORAGE DISEASE
o are inherited disorders of lysosomal hydrolase enzymes
o Results in accumulation of gangliosides and glycolipid
substrate
o accumlation within lysosomes of neurons and glia
throughout the nervous system.
HPILUDARIA
19

20. LEUKODYSTROPHY
 Caused by deficency b-galactocerebrosidease
 Resut in accumulation of galactocerebroside within
the nervous system.
HPILUDARIA
20

21. REFERENCES
 http://academic.brooklyn.cuny.edu/biology/bio4fv/page/
glycol.htm
 Reginald H. Garret, Charles M. Grisham. Biochemistry
 Donald J. Voet, Judith G. Voet, Charlotte W. Partt.
Principles of Biochemistry, International Edition.
 Thomas M. Devlin. Textboo of biochemistry with clinical
corelation. 6th edition
 Jeremy M. Berg, John L. tymoczk, Lubert stiyer.
Biochemistry, 5th Edition
 Robert K. Murray, Daryl K. Granner, Peter A. Mmayes,
Victor W. Rodwell. Harper’s Illustrated Biocheisty. 26th
edition.
HPILUDARIA
21

22. THANK YOU
HPILUDARIA
22