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.
