Glycerol backbone

Fatty acids derived from animal and vegetable sources generally contain an even number of carbon atoms siace they are biochemically derived by condensation of two carbon units through acetyl or malonyl coenzyme A. However, odd-numbered and branched fatty acid chains are observed ia small concentrations ia natural triglycerides, particularly mminant animal fats through propionyl and methylmalonyl coenzyme respectively. The glycerol backbone is derived by biospeciftc reduction of dihydroxyacetone. 

Fig. 8. Reactions of ttiglycetides at double bonds in the alkyl chain. R represents the glycerol backbone.

Although soaps have many physical properties in common with the broader class of surfactants, they also have several distinguishing factors. First, soaps are most often derived direcdy from natural sources of fats and oils (see Fats and fatty oils). Fats and oils are triglycerides, ie, molecules comprised of a glycerol backbone and three ester-linked fatty oils. Other synthetic surfactants may use fats and oils or petrochemicals as initial building blocks, but generally require additional chemical manipulations such as sulfonation, esterification, sulfation, and amidation. 

The numbering and nomenclature of glycerophospholipids present a dilemma in that the number 2 carbon of the glycerol backbone of a phos-... 

Phospholipids are important constituents of cell membranes and are of two kinds. Glycerophospholipids, such as phosphatidylcholine and phos-phatidylethanolamine, are closely related to fats in that they have a glycerol backbone esterified to two fatty acids (one saturated and one unsaturaled) and to one phosphate ester. Sphingomyelins have the amino alcohol sphingo-sine for their backbone. 

Glycerophospholipid (Section 27.3) A lipid that contains a glycerol backbone linked to two fatty acids and a phosphoric acid. 

Of the two major phosphohpid classes present in membranes, phosphoglycerides are the more common and consist of a glycerol backbone to which are attached two fatty acids in ester linkage and a phosphorylated alcohol (Figure 41-2). The fatty acid constiments are usually even-numbered carbon molecules, most commonly containing 16 or 18 carbons. They are unbranched and can be saturated or unsamrated. The simplest phosphoglyceride is phosphatidic acid, which is... 

FITC - RITC-PE FITC site 60-80 A from glycerol backbone region 414... 

Monoacylglycerols are the monoesters of glycerol that consist of only one fatty acid attached either to the position 1(3) or 2 of the glycerol backbone. However, because both diacylglycerols and monoacylglycerols are hydrolytic products of triacylglycer-ols and phospholipids, they may be present, if any, only in negligible levels in animal and plant tissues. 

Phosphonolipids (glycerophosphonolipids) found mainly in protozoans and marine invertebrates are lipids with phosphoric acid derivatives esterified to the glycerol backbone. 

Glycolipids consist of a sugar moiety attached to the glycerol backbone and are abundantly found in some algae, higher plant tissues, and microorganisms, whereas they may be present, if at all, only as trace constituents in animal tissues. 

The hydrophobic tail is provided by long-chain fatty acids attached to a glycerol backbone. The head group contains oxygen and may be positively charged or neutral. The name of the phospholipid is dictated by the head group. The head and tail are attached through a phosphate diester. 

Phospholipase A2 catalyzes cleavage of the fatty acyl chain from the second carbon of the glycerol backbone of phospholipids 577 Calcium-ion-dependent phospholipase A2 with a preference... 

A number of experiments have been conducted to establish various aspects of structure-activity relationships (SAR) of substrates. Although the greatest emphasis has been upon the nature and orientation of the side chains on the glycerol backbone, variations in the phosphate headgroup have also been explored. 

Figure 17. Order parameter profile for the two tails of DMPC bilayers. The chain closest to the head group is named sn and the other one sn2. Segments closest to the glycerol backbone are numbered t = 1, and the chain ends are t = 16. The lines are drawn to guide the eye...

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