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.

Detailed explanation-2: -The “head” of the molecule contains the phosphate group and is hydrophilic, meaning that it will dissolve in water. The “tail” of the molecule is made up of two fatty acids, which are hydrophobic and do not dissolve in water.

Detailed explanation-3: -The phosphate group is the negatively-charged polar head, which is hydrophilic. The fatty acid chains are the uncharged, nonpolar tails, which are hydrophobic.

Detailed explanation-4: -The heads (the phospho part) are polar while the tails (the lipid part) are non-polar. 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).

Detailed explanation-5: -Each phospholipid is amphipathic, with two hydrophobic tails and a hydrophilic head. The hydrophobic tails face inward towards one another, and the hydrophilic heads face outwards.