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Define lipids. Write briefly about their functions.

      

Define lipids. Write briefly about their functions.

  

Answers


Felix
Lipids are organic substances soluble only in organic solvents like chloroform, ether and benzene but insoluble in water.
Functions:
1. Lipids are structural components of cell membrane and nervous tissue.
2. Lipids present in myelinated nerves act as insulators for propagation of
depolarization wave.
3. Lipids present under skin act as thermal insulator against cold.
4. Lipids are energy source for man like carbohydrates.
5. Lipids like steroids function as hormones.
6. Lipids present around kidney act as padding and protect kidney from mechanical injuries.
7. Lipids serve as vitamins.
8. Lipids are part of lipoproteins present in blood plasma.
9. Absorption of fat soluble vitamins requires lipids.
10. Essential fatty acids a kind of lipids are essential for life.
11. Lipids act as microbicides and fungicides.
12. Some lipids function as surfactants.
13. Lipids are involved in immune response.
14. Lipids act as mitogens.
15. Some lipids serve as precursors for the formation of complex lipids.
16. Due to its high energy and water output on oxidation mammals including humans prefer to store energy in the form of lipid only.

What are the functions of lipids?

• They are a source of energy when oxidized. They yield more energy compared to carbohydrates when oxidized per unit weight. However, they are less preferred as source of energy because they require a lot of oxygen to oxidize. In addition, they are insoluble hence not easy to transport to respiratory sites.
• They are a source of metabolic water. When oxidized, they yield a lot of metabolic water. This explains why some desert animals such as camels store large quantities of fat in their bodies.
• Lipids offer protection to internal organs as they are deposited around them to act as shock absorbers.
• Lipids provide heat insulation when stored underneath the skin as they are poor conductors of heat hence do not conduct heat away from the body. Organisms in cold areas tend to be short and plump as they have fatter fat adipose.
• Lipids form structural compounds for instance phospholipids in cell membrane.
• Complex lipids such as waxes in leaves help minimize water loss through transpiration.
• Some lipids mediate communication between cells.
Anganifelix answered the question on May 10, 2018 at 18:34


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