Lipids: Definition, Structure, Function & Examples

Definition of Lipids

Lipids refers to a group of compounds such as oils, steroids, waxes, and fats that we can find in living organisms.

Moreover, eukaryotes and prokaryotes both possess these that play an important role biologically. For instance, membrane formation, protection, insulation, energy storage, cell division, and more. Besides, in medicine lipids refer to blood fats.

Structure of Lipids

They are made of a triglyceride that is made from alcohol glycerol and fatty acids. In addition, this basic structure yields great diversity in them.


Moreover, more than 10,000 kinds of it have been found so far. Many works with a huge diversity of proteins for material transport and cellular metabolism.

Besides, they are considerably smaller than proteins.

Examples of Lipids

One of the types of lipid is fatty acids that serve as a building block for other lipids as well. Also, fatty acid contains a carboxyl (-COOH) groups bound to a carbon chain with attached hydrogen and this chain is insoluble in water.

Besides, fatty acid can be unsaturated or saturated. Moreover, when unsaturated fatty acid combines with triglycerides it tends to yield oils.

Whereas, when saturated fatty acid combines with triglycerides it forms solid fats at room temperature.

Cholesterol is another example of lipids. Furthermore, it arranges into a rigid ring of five or six carbon atoms with attached and a flexible hydrocarbon tail.

Besides, the first ring that is hydroxyl group is water-soluble but the rest of the water molecule is water-insoluble.

Polyunsaturated Fatty Acids (PUFAs) aids in membrane fluidity of lipids. Also, it contributes to cell signalling related to neural information and energetic metabolism.

Functions of Lipids

In an organism life, they play several roles. They also make protective barriers. Moreover, in plants, they comprise of cell membranes and some structure of cell wall.

Moreover, they provide energy to plants and animals. Also, they often work along with proteins. Besides, their work can be affected by changes to their polar head groups along with their chains.

Moreover, phospholipids form the base for lipid bilayer, by their amphipathic nature that makes up cell membranes. Also, the outer layer of the lipid relates with water whereas the inner layer exists as an elastic oily substance.

Most noteworthy, they participate in cell division because it regulates lipid content subject upon the cell cycle.

Besides, a minimum of 11 lipids is involved in the cell cycle activity. Also, they help with the mechanical aspects of the division of membrane stiffness.

Also, it provides protective barriers for specialized tissues such as nerves. Furthermore, the myelin sheath that surrounds the nerve comprises lipids.

In addition, they provide a huge amount of energy from consumption and they have twice the amount of energy as carbohydrates and proteins.

They are also stored in the body and when needed are breakdown to form energy. Also, they make ATP (Adenosine triphosphate) to the power cell.

Besides, they also give necessary energy for plants metabolic processes and signals between cells.

Although in animals lipid serves as insulation from the environment and as protection for vital organs. Besides, they provide waterproofing and resistance.

Also, they play a role in cell signalling because in the peripheral and central nerves systems lipids control the fluidity of membranes and aid in an electrical signal spread.

Furthermore, they assist in the stabilization of synapses. Moreover, they are essential for growth and healthy immune system and reproduction.

Solved Question for You

Question. Among the following which one is not a lipid?

A. Steroids
B. Waxes
C. Cholesterol
D. Megaphone

Answer. The correct answer is option D. Because it is an acid.

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