LIFE SCIENCE

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: -Phospholipids consist of two hydrophobic “tails, ‘’ which are fatty acid chains, and one hydrophilic “head, ‘’ which is phosphate group.

Detailed explanation-3: -The heads, which form the outer and inner linings, are “hydrophilic” (water loving) while the tails that face the interior of the cell membrane are “hydrophobic” (water fearing). Water is attracted to the outsides (red) of the membrane but is prevented from going through the non-polar interior (yellow) layer.

Detailed explanation-4: -The plasma membrane is made of a phospholipid bilayer. A single phospholipid has a hydrophilic head and a hydrophobic tail.