What is the main component of the cell membrane? Why is it the main component?
1 Answer
If we count molecules, the main component of the cell membrane is phospholipid material.
It provides the container for the cell contents and allows only small uncharged molecules to pass through while keeping larger molecules at bay.
The major components of a cell membrane are phospholipids, glycolipids, proteins, and cholesterol.
The cell membrane contains more protein by mass, but the molar mass of a protein is about 100 times that of a lipid. So, bacterial and mitochondrial membranes have about 30 lipid molecules for every protein, and most of these are phospholipids.
Most phospholipids contain two fatty acids, glycerol, a phosphate group, and a simple organic molecule such as choline.
The phospholipids form a lipid bilayer or membrane in which the hydrophobic tails all line up to avoid the water inside and outside the cell, while the hydrophilic heads point toward the water.
The phospholipid bilayer serves two major functions.
1. As a container for the cell contents.
It separates the cell contents from the surrounding environment.
2. As a police officer to control the movement of molecules into and out of the cell.
The interior of the phospholipid bilayer is nonpolar, so only small uncharged molecules like oxygen (
Large molecules cannot pass through the phospholipid bilayer.
