Examples of Lipids | Their Structure and Function in Biology

Lipids are macromolecules that are insoluble in water. They are present in living organisms and also distributed in nature

Examples of lipids include

  1. Oils
  2. Fats
  3. Waxes
  4. Phospholipids
  5. Sphingolipids
  6. Steroids
Sl.NoType of lipidLipid nameSource
1OilsPeanut oil (arachis oil)Peanut or ground nut
2Sesame oilSesame seeds
3Olive oil
4FatsButterDairy products
5clarified butterDairy products
6MargarineVegetable oil + water
7Hydrogenated vegetable fatVegetable oil
8EicosanoidsProstaglandins The cell membrane (arachidonic acid)
9Leukotrenes
10Thromboxane Cell membrane
11SteroidCholesterolSynthesizied in the body.
12Ergosterolplants, yeast
13ButterMilk
14Galactosylceramidebrain

Lipids are one of 4 significant macromolecules (organic compounds) of our body.

They are taken from external sources like food and edible oils.

But, some of them are made in the body from excess carbohydrates.

Many types of lipids vary in structure, properties, and functions in the body.

They are insoluble in water and hence called hydrophobic.

Types of Lipids

Lipids are of two types as

  1. Simple lipids
  2. Compound lipid.

Simple lipids

These are the ones that are ester of fatty acid and alcohol. They are again of three types as

a) Neutral fats (glycerides) 

  • They have an ester of fatty acid and glycerol.
  • They tend to accumulate in our bodies and contribute to weight gain.
  • At room temperature, they are solid in nature.

Example: Butter

b) Oils

  • Like fats they are also ester of fattyacid and glycerol but are liquids at room temperature.

Ex: all edible oils

c) Waxes

  • These are also esters but have fatty acids linked with non-glycerol alcohol. 
  • This alcohol is a high molecular weight monohydric alcohol.

Ex: Bee wax.

  • The fats are stored in the body and are used in times of starvation.

These are of different types based on the fatty acid in them.

Fatty acid Structure

  • Lipids are chemically the esters of long-chain fatty acids with alcohols.
  • They have the following formula.

HOOC-(CH)2-CH3 fatty acids

lipid structure
fats/oils chemistry having an ester of glycerin moiety and fatty acid.

These fatty acids are obtained from plantsanimals (meat), and even minerals.

Compound lipids

  • They are mostly involved in the formation of membranes of the body cells.

They are of different types like

  1. Phospholipids
  2. Sphingolipids
  3. Steroids

Phospholipids

  • They have phosphate groups in their chemical structure.
  • The phosphate moiety determines the water permeable nature of the membrane it forms.

In general, a cell or plasma membrane has double layers of phospholipids, as shown in the image below.

plasma membrane
Plasma membrane with a phospholipid bilayer

Sphingolipids

  • These lipids have amine and other functional groups in their chemistry.
  • Sphingomyelin is a part of the nerve cell membrane.
Sphingolipids
Sphingosine structure [By: adobe]

Steroidal lipids.

  • These lipids are formed inside the body and sometimes are taken from external sources.
  • They have a cyclic ring-like structure in their chemistry, due to which they are called steroids.
  • These steroids, like cholesterol, are chemical constituents of the cell membrane.
cholesterol structure.

Frequently asked questions and answers

  1. Which lipid acts as a chemical messenger

    Lipids like prostaglandins, leukotrenes, hormone based lipids like the testosterone, estrogen act as chemical messengers.

  2. Where is most of a healthy person’s fat stored

    Fat in a healthy person is stored below the skin and mostly concentrated in the bums, soles, palms.

  3. What are the two main parts of a lipid molecule

    A fatty acid and alcohol.

  4. What are the building blocks of fats and oils

    Aliphatic Acids and alcohols act as building blocks of fats and oils.

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