HUMAN NUTRITION

Detailed explanation-1: -All of the lipid molecules in cell membranes are amphipathic (or amphiphilic)-that is, they have a hydrophilic (“water-loving”) or polar end and a hydrophobic (“water-fearing”) or nonpolar end. The most abundant membrane lipids are the phospholipids. These have a polar head group and two hydrophobic hydrocarbon tails.

Detailed explanation-2: -Lipids are hydrophobic (“water-fearing”), or insoluble in water. Lipids perform many different functions in a cell. Cells store energy for long-term use in the form of lipids called fats. Lipids also provide insulation from the environment for plants and animals.

Detailed explanation-3: -A phospholipid is a lipid that contains a phosphate group and is a major component of cell membranes. A phospholipid consists of a hydrophilic (water-loving) head and hydrophobic (water-fearing) tail (see figure below).

Detailed explanation-4: -Steroids. Steroids are another class of lipid molecules, identifiable by their structure of four fused rings. Although they do not resemble the other lipids structurally, steroids are included in lipid category because they are also hydrophobic and insoluble in water.