Question

How do the non-polar hydrophobic tails/polar hydrophilic heads in the phospholipid play a role in cell membrane formation?

Answer 1

All living organisms are made up of cells. The cell membrane, cytoplasm, cell organelles, and some inclusion bodies make up the cell. Cell membrane/ plasma membrane encloses the cytoplasm, inclusion bodies, and the various cell organelles. It protects the inner cell components and also controls the substances that enter or leave the cell (selectively permeable).

Complete answer:
The fluid mosaic model was proposed by Singer and Nicholson. Their model is the model that best explains the structure of the cell membrane.
The cell membrane is composed of proteins and phospholipids. The proteins present are globular proteins. The phospholipids present are amphipathic i.e. have both hydrophobic and hydrophilic components. Each phospholipid consists of a head made up of glycerol and phosphate group, attached to this head are two fatty acid chains.
The head is polar and hydrophilic while the fatty acid end is hydrophobic and nonpolar, contributing to the amphipathic nature of the phospholipid. Two layers of phospholipids are arranged in such a way that the hydrophobic tails face each other.
According to the fluid mosaic model, this phospholipid bilayer can show two types of movement, the transition movement, and the flip flop movement. The extrinsic and intrinsic globular proteins are found all around the phospholipid bilayer.
The cell membrane as mentioned before is selectively permeable. It allows fat-soluble substances and water-soluble substances to pass through it. The non-polar hydrophobic tail of the phospholipid allowed fat-soluble substances to easily pass through.

Note: A semipermeable membrane will allow molecules to pass through based on their size. Smaller molecules can easily pass through. A selectively permeable membrane will allow molecules to pass through regardless of their size.
If the cell requires the molecule, a selectively permeable membrane will allow a larger particle to pass. At the same time, it will not allow small unnecessary (not required by the cell) particles to enter. A semipermeable membrane will not show this distinction.