what is lipoWhat is lipids? and types of lipids in biology

What is lipids? and types of lipids in biology:- hello friends welcome to yourstudynotes.com Today we are going to tell you about lipids through  posts, hope you will like our post, so stay on our website, so let’s start.


Lipids are oily or greasy organic compounds found in the body of plants and animal. They are soluble in organic solvents  and give fatty acids on their hydrolysis. Lipids are compounds of carbon hydrogen and oxygen and the number of carbon and hydron atom is more than the number of oxygen atom. Lipids are non- polar and insoluble in water.

There are following three types of lipids:

  • Simple lipids.
  • Compound lipids.
  • Derived lipids

Simple lipids:-

Esters of fatty acids and different types of alcohols are called simple lipids.

Fatty acids:-

Fatty acids are monocarboxylic acid and can be produced by hydrolysis of fats. In fatty acids a long non-polar hydrocarbon chain is found attached with carboxylic group.

There are two categories of fatty acids.

Saturated fatty acids:-

Saturated fatty acid are generally based on acetic acid and have greater number of hydrogen in their carbon chain. Therefore they have only single bonds. There is predominance of saturated fatty acids in animal fat. for example propionic acid C2H5COOH, Palmitic acid  C15H31COOH, Stearic acid  C17H35COOH etc.

Unsaturated fatty acid:-

These fatty acids have lesser number of hydrogen atoms in their carbon chain than saturated fatty acid . Therefore they have one or more double bonds. fats of plants origin have more unsaturated fatty acids. There are two groups of unsaturated fatty acids.

Compound lipids:-

A part from fatty acid and glycerol some other compounds are also produced on the hydrolysis of compound lipids. Compound lipids include phospholipids, glycolipids and lipoproteins.

Derived lipids:-

Derived lipids are obtained by the hydrolysis of simple or compound lipids. They are made of 4 jointed rings. Sterids are most important derived lipids. Sterids include sterols and steroids. Cholesterol is the most frequently found sterid in animal. sex hormones and hormones of adrenal cortex are important steroids.

Sources of lipids:-

The fats occurring in the food can be grouped into two categories Visible fats and invisible fats. visible fats can be obtained from both plant and animal sources. For example butter, ghee , ground nut, mustard, coconut, sunflower and seasame oil. Animal fats provide us vitamins A and Dalso. The sources of invisible fats are cereals, pulses, oilseeds, milk, egg and meat.

Funcation of lipids:-

  1. In our body fats act as stored food or stored energy.
  2. Fats help in absorption of fat soluble vitamins like vitamins D and Vitamin A.
  3. Fats enhance the palatability of the food and help in quick evaquation of the stomach.
  4. When required fats are converted into carbohydrates.
  5. subcutaneous fat forms a heat insulating layer and also protects the body.
  6. Cholesterol forms structural component of the cell membrane.
  7. Certain steroids acts as precursors of some hormones.