Outline the structure and function of the plasma membrane

The plasma membrane is composed of a phospholipid by-layer. These phospholipid molecules are arranged in a double sheet which are stable yet fluid. These molecules have hydrophobic tails and hydrophilic heads, which gives the membrane its structure. Different types of proteins are arranged in the membrane, which give the membrane its properties. Some globular proteins are attached to the outside of the membrane which act as marker proteins. Some proteins are channel-forming proteins, which makes the membrane semi-permeable to smaller molecules and aid in diffusion and osmosis- which is defined as the movement of water moleclues from a high concentration to a low concentration across a semi-permeable membrane. This type of membrane structure is known as the fluid mosaic model.