Introduction

• The plasma membrane, also known as the cell membrane, is a semipermeable membrane that surrounds all cells, separating the interior of the cell from the external environment.

• Sure! Here are the 3 functions without explanation:

  1. Selective permeability

  2. Cell communication and signaling

  3. Structural support and protection

• The requisite barrier is provided by the plasma membrane, which forms the cell’s outer skin.

Structure

• 5 Main parts of Plasma Membrane :

  1. 1. Phospholipid Bilayer:

     This is the primary structural component of the membrane, forming a double layer with hydrophobic fatty acid tails facing inward and hydrophilic phosphate heads facing outward. 

  2. 2. Integral Proteins:

     These proteins are embedded within the phospholipid bilayer and can span the entire membrane, acting as channels, transporters, or receptors. 

  3. 3. Peripheral Proteins:

     These proteins are loosely attached to the inner or outer surface of the membrane and can play roles in signaling, cell adhesion, and structural support. 

  4. 4. Carbohydrates:

     These are attached to lipids (glycolipids) and proteins (glycoproteins) on the outer surface of the membrane and are involved in cell recognition and signaling. 

  5. 5. Cholesterol:

     This sterol is found in animal cell membranes and helps to regulate the fluidity and stability of the membrane.