Question #e9191
1 Answer
The cell membrane is best described using the fluid mosaic model.
Explanation:
The primary component of the cell membrane is the phospholipid molecule - because it is amphipathic it has a distinctly hydrophyllic head group (phosphate) and a hydrophobic tail group (fatty acid chain).
These molecules will self assemble into a phospholipid bilayer , with the polar group migrating to the surface (water based environment) and the non-polar chains projected inwards toward one another forming a water-proof barrier between the contents of the cell and its environment.
This membrane is said to be semi-permeable - particles that are uncharged and small are able to migrate across the membrane by squeezing in between the fatty chains. Large and charged particles are either repelled by the non-polar region or can't squeeze in-between the chains.
This membrane also included embedded proteins and carbohydrates that are used for cell-to-cell recognition, channels that actively move solutes in both directions as needed by the cell, hormone receptors, etc. The molecule **cholesterol ** is found in the membrane and gives the animal cell membrane greater structural integrity and security.
