Senin, 15 April 2013

Glycolipids and their classification


Glycolipids are components of the membrane in species ranging from bacteria to humans especially in those organisms that live in conditions of serious rare. The most likely function of glycolipids in membranes is based on their ability to pass through hydrogen bonding via glycosyl interlipid large head groups; Therefore they provide reliability for architectural membranes of organisms. Furthermore, since architectural components of the cell membrane, play a key role in cellular functions such as cell-cell communication, as components of the receptor, as anchors for proteins and as regulators of signal transduction.

Main Idea:

The glycolipid term represents any compound containing one or more monosaccharide residues, limited by a glycosidic bond to a hydrophobic moiety as an acylglycerol, a sphingoid, a ceramide (N-acylsphingoid) or a prenyl phosphate. Their role is to provide energy and also serve as markers for identification of cellphones.

In addition, glycolipids offer a molecular basis for clustering of signal transducers. The limited relationship between cholesterol and glycolipids in the layer of tissue are the power that separates them from phospholipids which remain liquid in features.

Classification of Glycolopids:

Glycolipids are classified as follows:

Glycoglycerolipids: the term glycoglycerolipid is used to assign glycolipids containing ID, mono-or trisaccharides linked glycosidically to the hydroxyl group of DIGLYCERIDES. Monogalactosyl-diacylglycerols and digalactosyldiacylglycerols are the primary elements of the various walls of glycolipid chloroplasts and these too are the most abundant fats in all photosynthetic cells, such as those of higher plants, plankton and some bacteria.

The term sulphated glycosphingolipids: is fat containing at least a monosaccharide residue linked to ceramide moiety. Ceramides are amides of fatty acids with long chains or trihydroxy bases. The acyl group of ceramide is usually a long chain saturated or monounsaturated fatty acids. Glycosphingolipids are divided as follows:

Neutral glycosphingolipids: these glycolipids constitute one or more glycosyl ceramide moiety that come up with for example: monoglycosylceramides cerebrosides Cerebrosides are where glucose or Galactose sugar residues are linked via linkage or foreign to the main alcohol of ceramide. Galactosylceramides are found in all the nerve tissue, but they may amount to 2% of the dry weight of the brain and the 12% of white matter. Glucosilceramidi (Glcs1-1 ‘ Cer) is found in the lower stages in animal tissues, such as the spleen and red blood cells, as well as in nerve tissue.

Oligoglycosylceramides: Glycosphingolipids which contains more than one functional group of glucose is supposed to be the oligoglycosylceramide. They are essential components of cell membranes of eukaryotic organisms and some viruses. The most essential and abundant of oligosylceramides is beta-D-galactosyl-(1-4)-beta-D-glucosyl-(1-1)-ceramide, also known as lactosylceramide (LacCer).
Acidic glycosphingolipids: they are divided into two groups:

Sulfoglycosphingolipids: They are sometimes called as “sulfatides” or “sulfatoglycosphingolipids” too. These are Glycosphingolipids holding a sulfate ester group connected to the carbohydrate fraction. Sulfate is produced mainly by foreign 3-galactosylcerebrosides sulfate (Foreign Affairs-Galactosyl-3-sulfate). They are mostly found in cells that are very dynamic in the transport of sodium like sodium glands, kidneys and gills.

Gangliosides: this group includes molecules composed of Glycosphingolipids ceramide linked by a glycosidic bond to a cycle of oligosaccharides containing sialic acid and hexose units. These fats can amount to 6% of the body weight of lipids from the brain. The typical monosialo-ganglioside GM1 ganglioside is.

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