examples of lipids sources of lipids definition lipid classification simple lipid compound lipids derived lipids Miscellaneous lipids biomedical importance

1. SIMS 305- Clinical Biochemistry
Lipids
Dr. Ali Raza
Centre for Human Genetics and Molecular Medicine (CHGMM),
Sindh Institute of Medical Sciences (SIMS), SIUT.

2. Lipids
 Contents
•Examples of lipids
•Sources of lipids
•Definition
•Classification:
Simple Lipids
Compound Lipids
Derived Lipids
Miscellaneous
•Biomedical Importance

3. Examples of lipids
 Oil
 Fats
 Waxes
 Butter
 Mayonnaise
 Ghee
 Cream
 Cheese

4. Sources
Plants
• Vegetable oil, Sunflower oil, Corn oil, Soybean oil
•Cotton seeds oil
•Pumpkin seeds
•Nuts and cereals
Animals
•Eggs
•Fish

5. Lipids
• Heterogeneous group of organic substance
• Bloor criteria(1943) classified lipids based on their
chemical composition
• Insoluble in water
•Soluble in Organic Solvents (Chloroform, Acetone)
•Relationship to the fatty acid as “Ester”
•Utilization by living organism

6. Lipids
 Ester of (fatty acids with) various alcohols
 Fatty acids: Hydrocarbon chain with a carboxylic
acid at one end.
Fatty acids
Alcohol

7. Ester bond
• An ester forms when a hydroxyl reacts with a
carboxylic acid, with loss of H2O.
Formation of an ester:
O O
R'OH + HO-C-R" R'-O-C-R'' + H2O

8. Lipids
Ester of fatty acids with various alcohols
Fatty acids Alcohol

9. Lipids Classification
I- Simple lipids: FA + Alcohols
II- Compound lipids :
FA + Alcohols + X (Phosphoric Acid)
III- Derived lipids: On hydrolysis yields
i) FA
ii) Alcohols
iii) Glycerides
IV- Miscellaneous

10. I- Simple lipids
“ Ester of fatty acids with various alcohols”
a- Neutral Fats
b- Waxes

11. Neutral Fats
Triesters of fatty acids with glycerol
E.g.
• Triglycerol
• TGs

12. I- Simple lipids
b- Waxes:
“ Ester of fatty acids with higher monohydroxy aliphatic
alcohols”

13. b- Waxes
i) True waxes:
Esters of higher fatty acids with higher
straight chains alcohols
Examples:
•Beeswax
•Carnauba wax

14. b- Waxes
ii) Cholesterol Esters:
(Cholesteryl ester)
Esters of higher fatty acids with cholesterol

15. b- Waxes
ii) Vitamin A and D Esters:
Esters of higher fatty acids with vitamin A and D

16. II- Compound lipids
Esters of fatty acids containing other groups or in addition
to an alcohol and fatty acids.
FA + Alcohols + X (Phosphoric Acid)

17. II- Examples of Compound lipids:
Phospholipids: lipids contain Phosphoric acid,
nitrogenous base & other substituents
Glycolipids: lipids contains carbohydrates
 Sulfolipids: lipids possess Sulphate groups
Aminolipids : Proteolipids
Lipoprotein: lipid attach to protein

18. Phospholipids
contains Phosphoric acid, nitrogenous base and other
substituent in addition to fatty acid and glycerol.

19. Examples of Phospholipids
Phosphatidyl choline (Lecithin)
Phosphatidyl ethanolamine (Cephalin)
Phosphatidyl inositols (Lipositols)
Phosphatidyl serine
Plasmalogens
Sphingomelins

20. Structure of Phospholipids

21. Glycolipids
lipids contains carbohydrates
• Contains alcohol (Sphingosine or Sphinogol) and
nitrogenous base in addition to fatty acid
• Phosphoric acid and glycerol are absent

22. Glycolipids
Two types of Glycolipids
Cerebrosides
Gangliosides

23. III-Derived lipids
• Derivative obtained on hydrolysis of simple and
compound lipids and exhibit lipid characteristics
Fatty acids (FA)
Glycerides (monoacylglycerol or diglycerides, glycerol)
Alcohol: High molecular weight , straight chain of alcohol
yield on wax hydrolysis
E.g. Glycerol, cholesterol

24. IV- Miscellaneous
 Aliphatic hydrocarbons such as iso-octadecane,
E.g; found in liver fat
 Hydrocarbon found in bee wax and animal waxes
 Carotenoids
 Vitamin E
 Vitamin K

25. Importance of Lipids
• Energy source or fuel: 9.5 C/ gram
• Phospholipids and Lipoprotein constituents of Cell
walls and cell organelles
• Lipoprotein are carrier of triglycerides, cholesterol,
Phospholipids
• Insulating effect in the body
• lipids are necessary for Fat soluble vitamins
(A, D, E and K )

26. 26
Reference:
Textbook Medical Biochemistry by Chatterjea,
Sixth Edition, Chapter 4
https://www.amazon.com/Textbook-Medical-Biochemistry-M-D-
Chatterjea/dp/9350254840