In general, phospholipids are a class of lipids that have a structural function rather than an energy function, they are the main components of cell membranes. Each phospholipid contains two “tail” fatty acids associated with a group of phosphorous-containing molecules.
Phospholipids serve to activate the body’s enzymes, since they act as messengers, transmitting signals into the cell . At present, many companies are dedicated to producing purified phospholipids, which are used in the production of materials and in nanotechnology.
What is the function of Phospholipids?
The main functions of phospholipids are:
- Phospholipids are an essential component in bile . These are responsible for transforming cholesterol into a soluble component. When the presence of phospholipids is scarce in the bile secretion process, it leads to the production of cholesterol gallstones.
- Another essential function of phospholipids is directed to the cell membrane , since it is composed of them. Phospholipids have an active characteristic called “amphipathic character”, a characteristic that ensures that they bind to each other through hydrophobic interactions.
- They interact with protein molecules , because their location in the cell membrane is with the polar heads facing the outer side, while the tails are facing the inside of the lipid bilayer.
What is the importance of phospholipids?
We can find phospholipids in all foods, because they are part of the cell membrane. All the functions of phospholipids are fundamental for the existence of the cell, as we know it. The importance of phospholipids is due to the following functions:
- They make up the structure of the cell membrane.
- They act as messengers in the transmission of signals inside the cell, activating enzymes.
- They are essential for the proper functioning of the lungs, thanks to their action as pulmonary surfactants.
- They regulate the level of cholesterol . Phospholipids fulfill the function of solubilizing cholesterol, an extremely important factor, because if there is a low level of concentration of them, it can produce cholesterol gallstones.
- They are precursors in the synthesis of leukotrienes, thromboxanes and prostaglandins.
- Phospholipids are essential to achieve optimal health, since without them the human body could not function properly.
Phospholipids in cell membranes
According to scientific studies, phospholipids, when suspended in water, can form a great variety of structures. Since these so-called antipathic molecules are arranged within an aqueous environment, they can congregate in solid spheres, their hydrophobic tails directed inward and their hydrophilic heads pointing outward, or spread out in sandwich sheets known as bilayers.
Bilayers composed of phospholipids have the ability to form hollow spheres that contain water, thus representing the basic foundation for all living cells. Many of the structures of phospholipids contain elements such as nuclei, mitochondria, and lysosomes.
What is the importance of phospholipids in the cell?
The importance of phospholipids in the cell is that they have an important class of biological molecules that serve functional and structural purposes of the human body. Its unique and special composition allows the formation of isolated “envelopes” within the aqueous environment of the human body, which recognizes that they are used by cells as raw material for important essential processes.
What is the structure of phospholipids like?
As its name implies, a phospholipid consists of a small portion of phosphate, a phosphorous atom attached to an amino acid, a vitamin, or other type of molecule, and a lipid portion, similar to a fat molecule.
The “head” or phosphate top of a phospholipid molecule is “hydrophilic”, meaning that it is capable of mixing with water. While in the case of lipid “tail”, it does not have the ability to mix with water, that is, it has “hydrophobic” characteristics.
Specialist chemists give phospholipids the name “amphipathic”, this is due to the presence of two such dissimilar appendages on the same compound, this being a fundamental property for the continuous existence of each cell in the composition of the human organism.
Phospholipids can be broken down in the human body and used for energy production, just like many other lipid-containing molecules.
Studies show that phospholipids can be divided through the use of enzymes to form signaling molecules called chemokines , which represent a fundamental factor in the regulation of cell migration, enzyme production and other important cellular processes.
A phospholipid of both functional and structural character is sphingomyelin , which is responsible for forming the insulation that protects the nerves and simplifies the conduction of nerve impulses.
Characteristics of Phospholipids
- They are composed of a glycerol molecule, a saturated chain accompanied by another unsaturated fatty acid chain, one or two phosphate groups and a polar molecule that is attached to it.
- According to their structure, they have a head made up of the phosphate group (polar), which is attached to a tail made up of fatty acid chains (apolar).
- In the cell membrane, the apolar tails point inwards and the polar heads point outwards.
- They contain a hydrophobic portion, made up of fatty acids, and a hydrophilic portion, which is represented by phosphate groups and the molecules associated with them.
- In contact with water, phospholipid molecules can take the shape of a sphere, called a micelle. The polar (hydrophilic) portions are arranged at the peripheries, while the hydrophobic tails remain inside the micelles away from the water.
- Its arrangement is in the form of layers. In cells, the phospholipids that make up the biological membranes are arranged in the form of bilayers, this event occurs because the hydrophilic portions come into contact with the water of the external and internal media, while the hydrophobic ones remain located in the membrane, away from water, which has a sandwich-like appearance.
What are the types of phospholipids?
We can find different types of lipids or fatty acids, they are part of our body and are essential for its proper functioning. Phospholipids are unfriendly lipids, which means that one portion of them is soluble in water, while the other rejects it. These are a fundamental part of all active cell membranes.
The most abundant or essential types of phospholipids are the following:
They are made up of an unsaturated fatty acid and a saturated fatty acid plus a functional group. These in turn are divided into:
- Phosphatidylethanolamide : Represents the main component of cell membranes with a proportion of 70% divided into Aquilacifospholipids and Plasmallogens.
- Phosphatidylcholine : They are a fundamental part of the Surfactant Factor produced by type II pneumocytes.
- Phosphatidylserine : It works as a neurotransmitter and second messenger. Its precursor is Phosphatidylethanolamide.
- Phosphatidyl inositol : This is involved in the metabolic process of arachidonic acid.
- Phosphatidylglycerol : This is part of the cell membranes of the heart when forming Cardiolipin.
These are complex lipids that are derived from the 18-carbon unsaturated amino alcohol sphingosine. It is in turn divided into three families: Gangliosides, Globosides and Cerebrosides.
Foods rich in phospholipids
All foods contain phospholipids, but certain types of foods have more than others. If you want to take full advantage of the benefits offered by this type of lipid, you cannot stop including the following foods in your diet:
- Almonds and walnuts . In addition to their delicious taste, they are very rich in antioxidants and phospholipids. Thanks to their many characteristics, they are very useful for delaying cellular aging and regulating cholesterol. They provide a good amount of magnesium, folic acid and vitamins of group B.
- Egg yolks . It has phosphatidylcholine, a class of phospholipid that is very useful in reducing bad cholesterol. In the same way, this part of the egg is rich in vitamins, proteins and minerals that are of great benefit to health.
- Soy lecithin . This nutritional supplement ensures a good metabolism, in addition to having highly cleansing characteristics. It is very satisfying, so it can bring great benefits to people who want to lose weight or lead a healthier lifestyle.
Conclusion on the use of Phospholipids
Phospholipids represent one of the most important molecules in the human body. They serve to carry out a wide variety of structural and functional actions, such as providing the bilayers that allow cell formation to be possible.
Phospholipid synthesis takes place within cells, starting from simpler precursors derived from the diet. Group B vitamins, such as choline and inositol, essential fatty acids and amino acids in proteins are essential in the production of phospholipids.
Eating a balanced diet is the best way to ensure the necessary nutrients to carry out an adequate synthesis of phospholipids.
Dr. Samantha Robson ( CRN: 0510146-5) is a nutritionist and website content reviewer related to her area of expertise. With a postgraduate degree in Nutrition from The University of Arizona, she is a specialist in Sports Nutrition from Oxford University and is also a member of the International Society of Sports Nutrition.