Question

What is the function of the phospholipids in the cell membrane?

Answer 1

Hint: Plasmalemma is the layer where the embedded proteins are present in between the lipid molecules. This layer is found in the eukaryotic cells especially in the cells of the animal. It gives permission to substances for entry.

Complete answer
According to the fluid mosaic model the cell membrane is made up of proteins and lipids. The lipids are arranged within the membrane with a polar head towards the outside and tail towards the inner part. Proteins are placed in between the layers. These proteins present in between the lipid bilayer are called the embedded proteins. The membrane is made up of a lipid bilayer which helps in the passage of certain ions and molecules in and out of the cell and acts as a semi-permeable or selectively permeable membrane.

Additional information
The membrane now has got a modern view of the structure, which is known as the fluid mosaic model. In the year 1972, it was developed by S. J. Singer and G. L. Nicholson. Its three basic characters were introduced by them.
When the structure is looked at from above then the integral proteins (embedded proteins will form a pebble-like appearance and give rise to a mosaic patterned cell membrane. In the plane of the membrane, these proteins and the membrane lipids are capable of lateral movement, which is due to the fluid nature of lipid association.
The proteins where lipids were attached are movable along with the lipid molecules due to the quasi-fluid nature of the lipid bilayer. This fluid nature of the membrane helps in various processes that include secretion, cell growth, endocytosis, cell division, and in the formation of intercellular junctions, etc.

Note:
The embedded proteins are also known as the integral proteins or transmembrane proteins. Transmembrane protein channels and transporters help in the transportation of the small organic molecules such as sugars or amino acids.