<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, sterols, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)</n0:def-definition><n0:def-source>MSH2002_06_01</n0:def-source></n0:ComplexDefinition>
<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A class of hydrocarbon-containing organic compounds. Lipids are insoluble in water but soluble in nonpolar solvents and play important roles in living organisms: these roles include functioning as energy storage molecules, serving as structural components of cell membranes, and constituting important signaling molecules. Lipids can be subdivided into 2 groups: fatty acids and glycerides.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>