Examples of Lipids | Their Structure and Function in Biology

Lipids are macromolecules that are insoluble in water.

They are present in living organisms and are also widely 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)
9Leukotrienes
10Thromboxane Cell membrane
11SteroidCholesterolSynthesized in the body.
12Ergosterolplants, yeast
13ButterMilk
14Galactosylceramidebrain

Lipids are one of our body’s 4 significant macromolecules that are taken from an external diet.

Also, some of them are biosynthesized in our body as per need from excess carbohydrates and other sources.

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 esters 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.

Example: Butter

b) Oils

  • Like fats, they are also esters of fatty acid 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 acids in them. The fatty acids can be either saturated forms or unsaturated forms. The saturated fatty acids are

Fatty acid Structure

  • Lipids are chemically the esters of long-chain fatty acids with alcohols.
  • The elements carbon, hydrogen, and oxygen are structural components of fatty acids and 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, leukotrienes, and hormone-based lipids like testosterone, and 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 is mainly concentrated in the bums, soles, and palms.

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

    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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