Human Biochemistry, Volume 1 - Murray R. 1993

Bioenergetics and Metabolism of Carbohydrates and Lipids
Metabolism of Acylglycerols and Sphingolipids
Biomedical Significance

The Role of triacylglycerols in Lipid TRANSPORT AND STORAGE, as well as in the Pathogenesis of conditions such as obesity, Diabetes Mellitus, and hyperlipoproteinemia, will be discussed in detail in subsequent chapters. Phosphoglycerols, phosphosphingolipids, and glycosphingolipids are Amphipathic Lipids, making them ideally suited to serve as the primary components of Cell/30.html">The Plasma Membrane. Certain Phospholipids perform specialized Functions. For instance, dipalmitoyl lecithin is a key constituent of pulmonary surfactant, which is sometimes deficient in premature infants, leading to respiratory distress syndrome. Inositol-containing phospholipids act as precursors for second messengers in hormone action, whereas alkyl phospholipid functions as platelet-activating factor. Glycosphingolipids located on the outer leaflet of the plasma membrane, with their oligosaccharide chains exposed to the extracellular environment, are integral Components of the cell surface glycocalyx and appear to play critical roles, namely: 1) participating in cell-cell interactions, 2) acting as receptors for Bacterial toxins, such as cholera toxin, and 3) serving as determinants of Blood Groups (the ABO system). Currently, about a dozen glycolipid storage diseases (e.g., Gaucher disease, Tay-Sachs disease) have been characterized, which are caused by a deficiency in lysosomal Hydrolases that catalyze the degradation of Glycolipids.