Phospholipids

• Phospholipids replace a single fatty acid chain from a triglyceride with a single phosphate ion
• The phosphate portion of the triglyceride is hydrophilic because of the charge on the phosphate ion
• Phospholipids are said to be amphipathic since they have both polar and non polar sides
• A steroid is a lipid composed of four carbon rings
• Functional groups are the groups of atoms that determine the properties of a molecule.
• Cholesterol helps with cell membrane flexibility
• Most steroids are built from cholesterol
• Steroids can penetrate the cell membrane and bind to intracellular receptors because of their lipid/nonpolar nature