Lipids are biomolecules and include many substances like fats, oils, waxes, vitamins like A, D, E and K. The importance of lipids can be listed based on the uses and role in lifelike
- Storage and Heat generation
- Hardness to hand palm and soles
- Smoothness to the skin
- Formation of cell organelles
- Helps in cellular transport
- Partition of substances
- Better delivery
Lipids are widely distributed in the body and perform many functions like
Energy storage: The excess carbohydrates in the body are stored as fats in our body. This storage occurs in the adipose tissue. The fats produce more calories than carbohydrates and protein during the breakdown. This is beneficial during starving conditions as the body can generate energy from fats.
This stored fat is also useful for birds during long migrations. The fat in the body breaks down to produce the needed energy for long flights.
Hardness to palm and soles: Lipids are stored in adipose tissue which is present below the skin. But this is very thick in the buttocks, palms of hands and soles of the legs. These regions have a high level of physical load like sitting, holding or carrying the body. The presence of fat here helps to keep the skin hard, manage friction and also weight.
Besides this, fat is also present around critical organs in the body like the kidneys. This way it helps to absorb shocks during body movements.
Smoothness to the skin: The skin of humans is smooth due to the distribution of the fat layer beneath it. It is especially attractive in women as it imparts a smooth and soft look to the skin.
Another benefit of fat beneath the skin is that it minimizes heat loss to the surrounding environment. If there is excess heat, the body tries to reduce it by sweating instead.
Formation of cell organelles: Many cell organelles in the animals and plant cells are made of lipids. The organelles like the cell membrane, vesicles, mitochondria, endoplasmic reticulum, etc. have lipid membranes.
Especially the cholesterol, sphingolipids are present in these membranes. They provide elasticity, shape and also the movement of substances through them.
Helps in cellular transport: Cellular transport from outside to inside and vice versa is tightly controlled. This occurs by processes like diffusion, osmosis, etc. These processes are controlled by hydrophilic and lipophilic moieties of the cell membrane.
Partition of substances: The lipids are not soluble in water. Any substance having lipids in higher concentrations can act as hydrophobic. That means, they are readily soluble in oils but not in water. This property has many benefits to a man like
a) Ease of separation
b) Ease of purification.
Purification of plant and animal tissue extracts is more natural. The lipid components move into organic solvents like the petroleum ether, hexane, etc. making it easy to separate by a separating funnel.
Better delivery: The human body in medical terms is divided into two compartments. One is the water compartment while the other is the lipid compartment. The water compartment includes bloodstream and other fluids in the body cavities while the lipid compartment includes the brain and other deeper tissues and cells.
When a drug or a substance is taken, it distributes into these compartments based on its chemistry. If the drug is hydrophilic, it distributes into the blood and other fluids but may not reach the brain and other deeper most tissues. Similarly, when a lipophilic substance is given, it reaches the brain and other deeper tissues faster. Then it starts to come back to the water compartment.
This phenomenon is widely used in medicine to target drugs. This method minimizes wastage of drugs and other unwanted side effects.
If a drug has to act on the brain, it is made lipophilic by chemical modification. So, when administered, it reaches the brain first and shows its action. Then it comes back to the water compartment by which time its effects are lowered due to decreased concentration.
Food: Lipids like fats, butter, and oils from plant seeds are widely used in food. Frying is a way of cooking where food is immersed in hot edible oils. This is both nutritious and also adds to the taste of the food. The method helps to cook the food fast and also gives brittleness to the material. This is one of the ways by which humans can consume essential fatty acids.
These edible oils are extracted from groundnut, sunflower, olive, mustard, and other plant seeds.