Lipids are organic compounds that contain hydrogen, carbon, and oxygen atoms, which form the framework for the structure and function of living cells. They are not soluble in water as they are non-polar, but are thus soluble in non-polar solvents such as chloroform.
Examples of Lipids: They include butter, ghee, vegetable oil, cheese, cholesterol, and other steroids, waxes, and fat-soluble vitamins. All these compounds have similar features, i.e. insoluble in water and soluble in organic solvents, etc.
Properties of Lipids
They are a family of organic compounds, composed of fats and oils. These molecules yield high energy and are responsible for different functions within the human body. Here some important characteristics of Lipids.
- They are oily or greasy nonpolar molecules, stored in the adipose tissue of the body.
- These are a heterogeneous group of compounds, mainly composed of hydrocarbon chains.
- A lipid is energy-rich organic molecules, which provide energy for different life processes.
- These are a class of compounds characterized by their solubility in nonpolar solvents and insolubility in water.
- A lipid is significant in biological systems as they form a mechanical barrier dividing a cell from the external environment known as the cell membrane.
Types of Lipids
These are broadly classified as Simple and complex lipids.
Esters of fatty acids with various alcohols.
- Fats: Esters of fatty acids with glycerol. Oils are fats in the liquid state
- Waxes: Esters of fatty acids with higher molecular weight monohydric alcohols
Esters of fatty acids containing groups in addition to alcohol and fatty acid.
- Phospholipids: These are containing, in addition to fatty acids and alcohol, a phosphoric acid residue. They frequently have nitrogen-containing bases and other substituents, eg, in glycerophospholipids the alcohol is glycerol and in sphingophospholipids the alcohol is sphingosine.
- Glycolipids: They containing fatty acid, sphingosine, and carbohydrate.
- Another complex lipid: They such as sulfo and amino lipids. Lipoproteins may also be placed in this category.