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Glycolipid. Glycolipids are lipids with a carbohydrate attached by a glycosidic (covalent) bond. [1] Their role is to maintain the stability of the cell membrane and to facilitate cellular recognition, which is crucial to the immune response and in the connections that allow cells to connect to one another to form tissues. [2]
In 1827, William Prout recognized fat ("oily" alimentary matters), along with protein ("albuminous") and carbohydrate ("saccharine"), as an important nutrient for humans and animals. [13] [14] For a century, chemists regarded "fats" as only simple lipids made of fatty acids and glycerol (glycerides), but new forms were described later.
Membrane lipids are a group of compounds (structurally similar to fats and oils) which form the lipid bilayer of the cell membrane. The three major classes of membrane lipids are phospholipids, glycolipids, and cholesterol. Lipids are amphiphilic: they have one end that is soluble in water ('polar') and an ending that is soluble in fat ...
Three fatty acid chains are bonded to each glycerol molecule. Each of the three -OH groups of the glycerol reacts with the carboxyl end of a fatty acid chain (-COOH). Water is eliminated and the remaining carbon atoms are linked by an -O- bond through dehydration synthesis. Both the adipose tissue and the liver can synthesize triglycerides.
Fatty acids are a major component of the lipids (up to 70% by weight) in some species such as microalgae [2] but in some other organisms are not found in their standalone form, but instead exist as three main classes of esters: triglycerides, phospholipids, and cholesteryl esters.
Phosphatidates are lipids in which the first two carbon atoms of the glycerol are fatty acid esters, and the 3 is a phosphate ester. The phosphate serves as a link to another alcohol-usually ethanolamine, choline, serine, or a carbohydrate. The identity of the alcohol determines the subcategory of the phosphatidate.
Lectins, or proteins that bind carbohydrates, can recognize specific oligosaccharides and provide useful information for cell recognition based on oligosaccharide binding. [ citation needed ] An important example of oligosaccharide cell recognition is the role of glycolipids in determining blood types .
General structures of mono-, di-, and tri-acylglycerides with names according to the stereospecific numbering Fatty acid Vegetable oils and animal fats contain mostly triglycerides, but are broken down by natural enzymes ( lipases ) into mono and diglycerides and free fatty acids and glycerol.