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How do phospholipids form the two layers of cell membranes?

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Synthesis of palmitate — Fat Palmitic acid is one of the most prevalent fatty acids occurring in the oils and fats of animals; it also occurs naturally in palm oil. It is generated through the addition of an acetyl group to multiple malonyl groups connected by single bonds between carbons. This structure forms a saturated acid—a major component of solid glycerides.

Phospholipids form the two layers of cell membranes due to their amphipathic nature, meaning each molecule contains both a water-attracting (hydrophilic) region and a water-repelling (hydrophobic) region.12

The structure of a phospholipid consists of a polar, hydrophilic "head" and two nonpolar, hydrophobic "tails" made of fatty acids. When placed in an aqueous environment, these molecules spontaneously self-assemble into a lipid bilayer to achieve the most thermodynamically stable state.123

In this arrangement:
* Hydrophilic heads face outward toward the surrounding water on both surfaces of the membrane.12
* Hydrophobic tails are directed inward, pointing toward one another and mingling in an organic, water-free environment.12

This "sandwich-like" structure effectively seals out the water medium from the interior of the membrane, creating a stable barrier that serves as the fundamental structural basis for all cell membranes.123