1. Bioorganic
Lipids
4/6/2019
Dr Seemal Jelani Chem-160

2. Introduction
Structurally heterogeneous class of bioorganic compounds include diverse types of molecules as
Fats and oils
Waxes
Cholesterol and its derivatives
Some vitamins
Prostagladins
All of them have limited solubility in water
4/6/2019
Dr Seemal Jelani Chem-160

3. Characteristics of Lipids
Large class of water-insoluble bioorganic compounds
In humans and many animals excess carbohydrates and other energy-yielding foods are converted to, and stored in the body as lipids known as fats
This is a major way of storing chemical energy and carbon atoms in the body
4/6/2019
Dr Seemal Jelani Chem-160

4. Lipids function as covering for nerve fibres
Fats and other lipids surround and insulate vital body organs, providing protection from mechanical shock and helping to maintain correct body temperature
Lipids function as covering for nerve fibres
Basic structural components of all cell membranes
Many chemical messengers in the human body “ hormones” are lipids
4/6/2019
Dr Seemal Jelani Chem-160

5. Classification By structure: Simple: fats, oils, waxes, steroids.
Complex: phospholipids, spingolipids, glycolipids.
The derivatives: hormones, fat-soluble vitamins
On the basis of whether they undergo hydrolysis reactions in alkaline solution:
Saponifiable lipids can be hydrolyzed under alkaline conditions to yield salts of fatty acids.
Nonsaponifiable lipids do not undergo hydrolysis reactions in alkaline solution.
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Dr Seemal Jelani

6. Lipids Lipids at a Glance Glycerol esters Hydrolysis products
Saponifiable lipids
Can be hydrolysed under alkaline conditions
Nonsaponifiable Lipids
Glycerol esters
Hydrolysis products
Non Glycerol esters
Not a Hydrolysis products
4/6/2019
Dr Seemal Jelani Chem-160

7. Waxes Triacylglycerols Fats and Oils 4/6/2019
Dr Seemal Jelani Chem-160

8. Phosphoacylglycerols
Sphingolipids
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Dr Seemal Jelani Chem-160

9. Nonsaponifiable Lipids
Steroids
Fat Soluble vitamins
Eicosanoids
Terpenes
Pheromones
4/6/2019
Dr Seemal Jelani Chem-160

10. Fats can be divided according to their chemical composition to:
Simple lipids:
These compounds are: esters of fatty acids with glycerol.
The triacylglycerol (TAG) is the simplest and most common fat. It is the form in which lipids are stored in the cell.

11. Saturated fatty acid Hexadecanoic acid (Palmitic acid)
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Dr Seemal Jelani Chem-160

12. Monounsaturated fatty acids
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Dr Seemal Jelani Chem-160

13. Trans
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Dr Seemal Jelani Chem-160

14. Saturated and unsaturated fatty acids
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Dr Seemal Jelani Chem-160

15. Polyunsaturated fatty acids Omega-3 and Omega-6 Fatty acids
Omega-3 and Omega-6 Fatty acids important in human body chemistry
Classification
The basis for the omega classification system involves the following considerations
A fatty acid has two ends
Methyl (CH3) end
Carboxyl (COOH) end
4/6/2019
Dr Seemal Jelani Chem-160

16. O CH3-(CH2)4-(CH=CH-CH2)4-(CH2)2-C OH Methyl end Carboxyl end
4/6/2019
Dr Seemal Jelani Chem-160

17. Omega-3 and Omega-6 Fatty acids
Polyunsaturated fatty acid with its endmost double bond three carbons away from its methyl end
Omega-6 Fatty acids
Polyunsaturated fatty acid with its endmost double bond six carbons away from its methyl end
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Dr Seemal Jelani Chem-160

18. 4/6/2019
Dr Seemal Jelani Chem-160

19. Essential Fatty acids
Needed by the human body and must be obtained from dietary sources because they cannot be synthesized within the body from other substances
Essential fatty acids:
1 Linoleic acid
2 Linolenic acid
4/6/2019
Dr Seemal Jelani Chem-160

20. Linoleic acid and Linolenic acid
Both are 18-carbon polyunsaturated acids
Linoleic acid is an omega-6 acid
Linolenic acid is an omega-3 acid
4/6/2019
Dr Seemal Jelani Chem-160

21. 4/6/2019
Dr Seemal Jelani Chem-160

22. Both contribute to proper membrane structure
Deficiency of Linoleic acid
Skin reddens and become irritated, infection and dehydration occur and liver may develop abnormalities and conditions will reverse on the restoration of the fatty acid
4/6/2019
Dr Seemal Jelani Chem-160

23. EPA (Eicosapentaenoic acid) DHA (Docosahexaenoic acid)
Both of these are starting points for the synthesis of a variety of other longer-chain polyunsaturated acids which are:
EPA (Eicosapentaenoic acid)
DHA (Docosahexaenoic acid)
Arachidonic acid major precursor of eicosanoids (substances that help regulate blood pressure)
4/6/2019
Dr Seemal Jelani Chem-160

24. EPA (Eicosapentaenoic acid) DHA (Docosahexaenoic acid)
Both of them are important constitutes of the communication membranes of the brain and its normal development, and also active in the retina of the eye
Sources:
Vegetable oils, meat and fish live in deep cold water are good source of linoleic acid and other omega-6 acids
4/6/2019
Dr Seemal Jelani Chem-160