CHEM 17-2 - Phosphoglycerides (Membrane Lipids) The most...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Phosphoglycerides (Membrane Lipids) The most polar lipids are found in membranes surrounding both individual cells and the organelles within the cell. The most abundant lipids in membranes are phospholipids (lipids that are phosphate esters), and primarily phosphoglycerides . Phosphoglycerides include two major types, plasmalogens and phosphatidates . In the latter, the molecule is identical to a triglyceride up to the phosphoric acid unit, which is esterified with another alcohol molecule other than glycerol. Two common phosphatidates include cephalins (with ethanolamine group) and lecithins (with choline group), where the other alcohol is ethanolamine or choline (amino alcohols). Both are important parts of brain and nerve tissue. Cephalins are involved with blood clotting, while lecithin, a component of cell membranes, is the major phospholipid in pulmonary surfactant which facilitates our respiration process. These molecules, like soaps, are amphipathic, and this nature is central to the structure and function of cell membranes. An emulsifying agent aids in the suspension of triglycerides in water, and lecithins (from soybeans, egg yolks) are used as such in foods (ice cream, mayonnaise). Many foods are emulsions (milk – butterfat emulsified in H 2 O). Nonglyceride Lipids (Sphingolipids) Sphingolipids are lipids not derived from glycerol . They are amphipathic, are structural components of cell membranes, and derived from the amino alcohol sphingosine. They include sphingomyelins and glycosphingolipids. The “simpler” ones are sphingomyelins , which each contain units from a fatty acid, phosphate, sphingosine, and choline. About 25% of the myelin sheath which surrounds the axon are sphingomyelins (humans), as these are essential to nerve transmission and proper cerebral function. Glycosphingolipids (glycolipids ) include cerebrosides, sulfatides, and gangliosides. Cerebrosides
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/09/2008 for the course CHEM 104 taught by Professor Nathan during the Spring '08 term at St. Francis PA.

Page1 / 4

CHEM 17-2 - Phosphoglycerides (Membrane Lipids) The most...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online