Difference Between Lipids and Fats

Lipid vs Fat

Every living being needs energy source to stay alive. Plants make their own energy, but most others have to gain this energy through a diet. Lipids or fats are found in plants and animals. It is a major constituent in living beings and belongs to one of the main classes of biomolecules and macronutrients. Lipids and fats are found in various food sources such as butter, margarine, meat, eggs, milk, cheese, vegetable oil, soy oil etc. These are digested by the enzyme lipase inside our body and are used for various metabolic processes such as cellular respiration. Some lipids and fats are used as cell/tissue constituents. But are lipids and fats the same thing? No. In fact, lipids are one of the major classes of biomolecules and fats a sub class of lipids.

What are lipids?

Lipids are a class of biomolecules. There are various types of lipids found in living organisms such as wax, fats, steroids, glycerides, phospholipids and fat soluble vitamins etc. They cater to a variety of biological functions like cell signaling, energy storage, structural components in cell membrane etc. The general characteristic feature of lipids is the hydrophobic or amphiphilic nature. This nature allows them to form vesicles and membranes in our cells. Phospholipids and cholesterol act as cell membrane constituents. Wax is produced as an excretion in animals as well as plants. Steroids are found as sex hormones, and other various chemicals regulating body functions. Most of these lipids are made by biosynthetic pathways inside our body. Lipids that are not producible is called essential lipids and are taken through diet.

What are fats?

Among the various lipid sub classes found inside our body, there is a class of lipids called glycerides. Glycerides could be either, monoglycerides, diglycerides or triglycerides depending on the number of fatty acid chains present in one fat molecule. Fats are the common name given to triglycerides. Triglycerides are made up of three fatty acid chains reacting with glycerol to form the esterified product triglycerides. This is the major energy reservoir in mammals. The fat is stored in special cells called adipocytes (fatty cells). This tissue is present as a lining for internal organs protecting them from injuries and external pressure. Fats dissolve in organic solvents but do not dissolve in water. Fats could be classified as saturated fats and unsaturated fats, liquid fats and solid fats. Unsaturated fats can be further divided into cis fats and Trans fats depending on the nature of hydrocarbon chains.

What is the difference between Lipids and Fats?

• Lipids are a major class of biomolecules. Fats (triglycerides) belong to the group glycerides, which is a sub class of lipids.

• Lipids can be hydrophobic (don’t dissolve in water) or amphiphilic (part dissolves in water), but fats, essentially, do not dissolve in water.