The concept of glycolipids and their classification, basic functions and differences

0
2017.09.07
295
Cholesterol

Glycolipid is a complex lipid, in the creation of which three components are involved: sphingosine, fatty acid and oligosaccharide. Glycolipids (biochemistry - the science that studies them) are present in animal plant organisms. Some microorganisms also contain this substance in their cells.

Glycolipids have two parts: the polar part - the "head" and the nonpolar part - the "tail". Thanks to this structure, they, together with phospholipids, form part of the cell membrane.

Content

  • Classification
  • Function of glycolipids
  • Characteristic difference

Classification

The dominant form of the substance that enters the tissue of animal organisms is glycosphingolipid. Its structure includes ceramide and the remains of sugars. As a result, two simple compounds are formed: glucosylceramide and galactosylceramide. The latter is considered the main glycosphingolipid of the brain. It is also an important structural element for nerve fibers.

According to biochemists, glycosphingolipid occurs in cells of other organs, where it is present in relatively small amounts. A larger volume in these tissues is occupied by glucosylceramide.

Glycosphingolipids concentrate in the outer layers of cells and participate in their contacts and interactions. A small part of glycosphingolipids can be considered antigens, for example, the Forssman antigen and compounds, which together with glycoproteins are used to determine the blood group according to the ABO system.

Function of glycolipids

Scientists can not say exactly what is the main property of glycolipids and their actions in the body. They admit that these substances play the role of surface receptor of bacterial toxin, which provokes severe diarrhea in the presence of cholera in the body. The toxin of this disease can penetrate only into those cells whose plasmatic membrane has only Gm1 ganglioside (such intestinal cells include).

Experts admit that the combination of harmful toxins can not be considered the only task of gangliosides, these glycolipids can work as receptors for some mediators that provide a normal intercellular communication.

If we consider the functions of these substances in the context of the general concept of lipids, then they provide the person:

  • Mechanical protection against damage.
  • Energy for normal life.
  • Warming. Especially it is characteristic for newborns. Up to a certain age, they have brown fat, which protects the body from hypothermia.
  • Thermal insulation of internal organs.
  • Assimilation of fat-soluble vitamins.
  • Minimizing the risk of atherosclerosis.
  • The production of steroid hormones in sufficient quantities.
  • Correct structure of cell membranes.

According to numerous biological studies, the lack of glycolipids in women leads to serious malfunctions of the menstrual cycle and pathology of the reproductive organs.

Characteristic difference

The main difference between phospholipids and glycolipids is the structure of these substances. Glycolipids, unlike phospholipids, are devoid of a phosphoric acid residue. To their molecules containing diacylglycerin, galactose and sulfoglucose molecules are attached via a glycosidic bond.

When comparing the chemical formulas of these two substances, one can see how they differ from each other.

Structure of phospholipids
Structure of glycolipids

As a rule, these compounds enter the membranes of plants and several species of algae. They are characterized by the presence of linoleic acid in the composition.

.. .