4 Important Components of Plasma Membrane or Cellular Membrane 

1. Two rows of phospholipids- The Lipid Bilayer.
2. Cholesterol
3. Transport proteins
4. Carbohydrate Chain.

1. Two rows of Phospholipids- The Lipid Bilayer

• Cellular Membrane or Plasma Membrane is made of molecules called phospholipids. Phospholipids have a head made of phosphate and two tails made of fatty acids.
• The heads are hydrophilic meaning that they are attracted to water or literally water loving.
• The tails however are hydrophobic meaning that they repel water literally hydrophobic means water fearing.
• Due to these properties phospholipids form two layers known as a phospholipid bilayer.
• With the hydrophobic tails facing each other and the hydrophilic heads facing the watery external environment and the watery cytoplasm inside of the cell so the water lovers get to be next to water and the water fearers can hide away from it
• A perfect arrangement of the phospholipid bilayer is the main component of the membrane and it is largely responsible for making the membrane semi-permeable.
• For the smaller and less charged Particle  it is easier to pass through the phospholipid bilayer bigger more charged Particles have a harder time to pass through.

Also Check – What would happen if the Plasma Membrane Ruptures or Breakdown?

2. Cholesterol

• The second membrane component is Cholesterol. 
• Cholesterol is a very important part of cell membranes ,It helps to stabilize the membrane and make it better at controlling what can pass through it.

3. Transport Proteins

• Proteins are another important part of the membrane 
• The most important Function of protein is transporting materials across the membrane especially if they have a hard time passing through the phospholipid bilayer

4. Carbohydrate Chain

• The fourth membrane component is carbohydrates; these are often involved in cell identification.
• Blood types for example are the result of membrane carbohydrates attached to proteins; these help to identify blood that belongs to you and distinguish it from foreign invaders.

All of these components of Plasma membrane or cell membrane work together to make the plasma membrane that surrounds all cells a critically important barrier needed for all life on earth