GENERAL HISTOLOGY

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: -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-3: -Phospholipids are a class of lipids whose molecule has a hydrophilic “head” containing a phosphate group and two hydrophobic “tails” derived from fatty acids, joined by an alcohol residue (usually a glycerol molecule).

Detailed explanation-4: -Phospholipid Bilayer Definition The fatty acid tails are hydrophobic, meaning they do not mix with water and are nonpolar. The heads, however, are made of the phosphate group and have a negative charge, making them hydrophilic and thus are able to mix with water.

Detailed explanation-5: -The hydrophilic head is composed of a choline structure (blue) and a phosphate (orange). This head is connected to a glycerol (green) with two hydrophobic tails (purple) called fatty acids. (D) This view shows the specific atoms within the various subregions of the phosphatidylcholine molecule.