Phospholipids are not only an exciting topic for researchers and biologists. But this topic is also relevant for each individual. Phospholipids play an important role in our human organism.
The following article is intended to provide all relevant questions and a definition of phospholipids. The most important properties are presented and the individual components for the structure are explained. In addition, practical relevance is established.
the essentials in brief
- Phospholipids are found in the body's major organisms such as the bone marrow, liver, heart and brain.
- They are the main component of biomembranes and separate the intracellular and extracellular space from each other.
- Phospholipids are made up of glycerol, phosphoric acid, and long-chain aliphatic compounds. A double lipid layer forms due to the hydrophobic (= water-avoiding) and hydrophilic (= water-loving) components.
Glossary entry: The term phospholipids explained in detail
The following glossary entry answers all relevant questions about phospholipids.
What are Phospholipids?
Phospholipids are among the complex lipids that have an ester bond with phosphoric acid.
Phospholipids belong to the membrane lipids and are therefore the main component of all cell membranes.
There they form a lipid bilayer (liposome) consisting of a hydrophilic (water-loving) head and two hydrophobic (water-avoiding) hydrocarbon tails. They are amphiphilic.
To be more precise, the membrane forms when the phospholipids with their non-polar areas (i.e. the fatty acid residues) come together. The polar regions of the molecule where the phosphate moiety is attached to the glycerol are tilted towards each other. This allows the intracellular space to be separated from the extracellular space and the molecules do not mix.
The hydrophilic area therefore consists of the glycerol and the phosphate group, which is often represented by the alcohol esterified on the phosphate group. The most important subgroup of the glycerophospholipids include phosphatidylethanolamine (kephalin, phosphatidylinositol and phosphatidylcholine (lecithin). The lipophilic area is usually located on the fatty acid residues (1,2,3,4,5">.
How are phospholipids structured?
Based on their chemical structure, phospholipids can be divided into the following two groups:
| Chemical substance | function |
|---|---|
| phosphoglycerides | Glycerol as the backbone |
| Phosphorus-containing sphingolipids | Derivation from sphingosine |
In addition, there are the so-called plasmalogens. Due to the linkage of the ether bridge and the unsaturated alcohol, instead of a fatty acid, the plasmalogen differs from the phosphoglycerides. They form 50% of the phospholipids.
hospholipids are amphiphilic, ie they consist of lipophiles and hydrophiles. From this it is possible for the phospholipids to form a boundary between different molecules. A double lipid layer forms in the water, with the hydrophilic parts of the molecule pointing towards the water and the lipophilic parts away from the water.
In addition to separating two periods of time, these chemical properties also ensure the fluidity of the membrane. Synthesized in the smooth endoplasmic reticulum, cells can be transported to their destination on the cell membrane in the form of vesicles.
The phospholipids present in the membranes can be broken down by various phospholipases. Degradation plays an important role in signal transduction (1,2,3,4,5">.
Where are phospholipids found?
Phospholipids consist of the compounds of fatty acids and phosphoric acids. They are therefore classified as complex fats. Phospholipids are commonly found in the following human organisms:
- bone marrow
- Brain
- liver
- Heart
They also play an important role in building the cell structure.
But there are also some foods that contain phospholipids:
- Seeds, roots, tubers of plants
- yeast, mushrooms
- Vegetable oil
How are phospholipids formed?
The main components of phospholipids are glycerol, phosphoric acid and long-chain aliphatic compounds.
Phospholipids have been studied in research for years. (Image source: Science in HD/ unsplash).
Due to their components and due to their hydrophobic (= water-avoiding) and hydrophilic (= water-loving) proportion in water, phospholipids form a double lipid layer (1,2,3,4,5">.
Conclusion
Phospholipids are particularly important for the human organism as they are responsible for the formation of the cell membrane. Depending on the state of the phospholipids, the degree of fluidity can be assumed.
The more unsaturated fatty acids in the membrane, the more permeable it is for water. Thus, the fluidity is increased. The double lipid layer thus performs a barrier function for molecules such as water.
References
- Structure and explanation of phospholipids
- Structure and explanation of phospholipids
- Synthetic phospholipids and the transport of other molecules across the bilayer membrane
- Explanation of the various substances in connection with the body
- Explanation of Phospholipids