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Unformatted text preview: Phospholipids look just like lipids except that one of the fatty acid chains is replaced by a phosphate (P0 4 3 ) group (Figure 3). Additional chemical groups (indicated by R in Figure 3) are usually attached to the phosphate group. Since the fatty acid tails of phospholipids are nonpolar and hydrophobic and the glycerol and phosphate heads are polar and hydrophilic, phospholipids are often found oriented in sandwichlike formations with the hydrophobic heads oriented toward the outside. Such formations of phospholipids provide the structural foundation of cell membranes. Steroids are characterized by a backbone of four linked carbon rings (Figure 4). Examples of steroids include cholesterol (a component of cell membranes) and certain hormones, including testosterone and estrogen....
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This note was uploaded on 11/10/2011 for the course PT 101 taught by Professor Staff during the Spring '10 term at Texas State.
- Spring '10